feat(build): fuzz testing and git-cliff changelog automation

Add FuzzParseBytes and FuzzSanitizeYAMLEscapes in internal/model/fuzz_test.go.
Both targets run as regular seed-based tests in CI (go test ./...) and can be
run continuously via `task fuzz` (default 30 s per target; FUZZ_TIME=60s to
extend). Fuzz corpus failures are saved to testdata/fuzz/ for regression.

Add cliff.toml configuring git-cliff to generate Keep-a-Changelog-compatible
release notes from Conventional Commits. New tasks: `task changelog`
(regenerate full CHANGELOG.md) and `task changelog-next` (preview unreleased
entries without writing). Requires git-cliff (brew/cargo install git-cliff).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,40 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 This project uses [Semantic Versioning](https://semver.org).
 
+## [0.2.27] - 2026-06-25
+
+### Added
+
+- **Fuzz testing** — `FuzzParseBytes` and `FuzzSanitizeYAMLEscapes` in `internal/model/fuzz_test.go` verify that neither the YAML parser nor the escape sanitizer panics on arbitrary input. Successful parses are also checked for structural integrity (non-nil pipeline, no empty job names). Run with `task fuzz` (default 30 s per target; set `FUZZ_TIME=60s` to extend). Found failures are saved to `testdata/fuzz/` for regression.
+
+- **Changelog automation** — `cliff.toml` configures [git-cliff](https://git-cliff.org) to generate Keep-a-Changelog–compatible release notes from Conventional Commits. `task changelog` regenerates `CHANGELOG.md` from the full git history; `task changelog-next` previews only unreleased commits without writing. Install git-cliff with `brew install git-cliff` or `cargo install git-cliff`.
+
+## [0.2.26] - 2026-06-25
+
+### Changed
+
+- **Same-stage job ordering** — when jobs within the same declared GitLab stage have `needs:` relationships between each other, the pipeline graph now splits that stage into topological sub-columns: jobs with no same-stage dependencies occupy the leftmost sub-column; jobs that depend on them are placed one sub-column to the right. Sub-columns use a narrower 20 px gap (vs. the 50 px gap between stages), and the stage header spans all sub-columns. Stages with no intra-stage `needs:` are unaffected.
+
+- **Graph links rendered behind job chips** — SVG connector lines (Bézier curves in DAG mode, bus-bar stubs in classic mode) are now drawn before the job chip rectangles, so connector lines pass behind chips rather than on top of them.
+
+## [0.2.25] - 2026-06-25
+
+### Added
+
+- **`when: on_failure` visual distinction** — SVG and HTML pipeline graphs now render failure-path jobs with a red status circle (`#d9534f`), an X-mark icon, and a dashed chip border. A new `on_failure` legend entry and Mermaid `classDef` entry are included.
+
+- **Job tooltip / detail panel** — every job chip in SVG and HTML output is wrapped in a `<g data-job="…"><title>…</title><desc>…</desc>` group. SVG viewers that support `<title>` show the job name on hover; `<desc>` carries `stage`, `when`, `image`, and `needs` details. In HTML output the sidebar reads these directly from the DOM.
+
+- **Multi-job connector accuracy** — classic mode (no `needs:`) now uses a bus-bar connector: horizontal stubs from every job in stage N to a vertical rail at the midpoint, then stubs from the rail to every job in stage N+1. The previous single center-to-center line left top and bottom jobs visually disconnected.
+
+- **Skipped / blocked state colouring** — `glint graph pipeline` now accepts the same context flags as `glint check` (`--branch`, `--tag`, `--source`, `--var`, `--changes`, `--changes-from`). Jobs that evaluate to `JobSkipped` in the given context are rendered with a grey circle (`#868686`) and dimmed job name. When no context flags are given, all jobs render with their normal colours.
+
+- **Interactive HTML output** (`--format html`) — `glint graph pipeline --format html` writes a self-contained `.html` file to `--out`. The page embeds the SVG inline with mouse-wheel zoom (centred on cursor), drag-to-pan, double-click-to-reset, and a collapsible sidebar showing job details on chip click. No external dependencies; works offline.
+
+- **Mermaid pipeline output** (`--format mermaid`) — `glint graph pipeline --format mermaid` prints the existing Mermaid flowchart (`pipeline.go`) to stdout. Suitable for pasting into [mermaid.live](https://mermaid.live) or embedding in Markdown documentation.
+
+- **`imageString` helper** — internal utility that extracts the image name from a `Job.Image` field that may be a plain string or a map (`image: {name: ..., entrypoint: ...}`); used by the tooltip desc builder.
+
 ## [0.2.24] - 2026-06-25
 
 ### Added

FEATURES.md

@@ -282,8 +282,29 @@ jobs or pipeline-level findings.
 | `pipeline` | GitLab CI-style SVG/PNG written to `--out` directory (default: `glint-out/`); converted to PNG when `rsvg-convert`, `inkscape`, or `magick` is available |
 | `all` | `includes` to stdout + `pipeline` file path to stderr |
 
+**`glint graph pipeline --format <FORMAT>`**
+
+| Format | Effect |
+|--------|--------|
+| `svg` (default) | Write GitLab CI-style SVG/PNG to `--out` |
+| `mermaid` | Print Mermaid flowchart to stdout (paste into [mermaid.live](https://mermaid.live)) |
+| `html` | Write self-contained HTML to `--out` with mouse pan/zoom and a click-to-open job-detail sidebar |
+
+**Visual distinctions in SVG and HTML output:**
+
+- **Regular** — blue circle with checkmark
+- **Manual** — orange circle with play triangle
+- **Trigger** — purple circle with chevron
+- **Delayed** — yellow circle with clock
+- **`when: on_failure`** — red circle (`#d9534f`) with X mark; dashed chip border
+- **Skipped** (with `--branch`/`--tag`/`--source` context flags) — grey circle, dimmed job name
+
 In DAG pipelines (any job has `needs:`) the pipeline graph uses job-to-job
-Bézier connectors instead of stage-to-stage lines.
+Bézier connectors. In classic mode a bus-bar pattern (vertical rail + per-job
+stubs) accurately connects every job across adjacent stages.
+
+Each chip carries a `<title>` and `<desc>` with stage, when, image, and needs —
+shown as a tooltip in SVG viewers and as a sidebar panel in HTML output.
 
 ---
 

README.md

@@ -6,7 +6,7 @@
 
 <p align="center">
   <a href="LICENSE"><img src="https://img.shields.io/badge/license-Apache%202.0-blue.svg" alt="License"></a>
-  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.24-blue.svg" alt="Release"></a>
+  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.27-blue.svg" alt="Release"></a>
 </p>
 
 > **Disclaimer:** This tool was built through iterative AI-assisted development with [Claude](https://claude.ai). It is experimental, incomplete, and not intended for production use. Coverage of GitLab CI keywords is best-effort and may lag behind GitLab's evolving spec. Use it at your own discretion — no correctness guarantees are made. Contributions and bug reports are welcome.
@@ -20,7 +20,7 @@ A local tool to validate and lint `.gitlab-ci.yml` pipelines without needing a G
 - **Simulates context** — `--branch`, `--tag`, `--source` flags evaluate `rules:if:` and `only`/`except` to show which jobs would be active, manual, or skipped; `--context branch=main --context branch=develop` prints a multi-column comparison table across multiple contexts in one run
 - **Multiple output formats** — `--format text` (default, ruff-style), `json`, `sarif` (GitHub Code Scanning / GitLab SAST), `junit`, `github` (PR annotations)
 - **Project config** — `.glint.yml` for rule suppression, severity overrides, token/URL defaults; `# glint: ignore RULE` for per-job inline suppression
-- **Graph visualization** — `glint graph` prints a terminal job tree; `glint graph pipeline` renders a GitLab CI-style SVG/PNG
+- **Graph visualization** — `glint graph` prints a terminal job tree; `glint graph pipeline` renders a GitLab CI-style SVG/PNG; `--format mermaid` emits a Mermaid flowchart; `--format html` produces a self-contained HTML file with pan/zoom and a job-detail sidebar; context flags grey out skipped jobs
 
 See [FEATURES.md](FEATURES.md) for the complete feature reference and lint rules table, and [ROADMAP.md](ROADMAP.md) for planned improvements.
 
@@ -69,11 +69,18 @@ task test         # run Go unit tests
 task lint-go      # run go vet
 task validate     # run the binary against all testdata fixtures
 task ci           # full check: vet → test → build → validate
+task fuzz         # run fuzz tests for the YAML parser (Ctrl-C to stop; FUZZ_TIME=60s to set duration)
+task changelog    # regenerate CHANGELOG.md from git history via git-cliff
+task changelog-next  # preview unreleased section (dry-run, no file written)
 task build-windows  # cross-compile for Windows x64 (requires a tagged commit → glint-<tag>.exe)
 task build-linux    # cross-compile for Linux x64 (requires a tagged commit → glint-<tag>-linux-amd64)
 task clean        # remove build artifacts
 ```
 
+**Optional tools:**
+
+- [git-cliff](https://git-cliff.org) — changelog generator used by `task changelog`. Install with `brew install git-cliff` or `cargo install git-cliff`.
+
 ## Project structure
 
 ```

ROADMAP.md

@@ -71,12 +71,14 @@ The SVG renderer and terminal tree cover the basic layout. These would bring it
 
 - ~~**Terminal job tree**~~ — ✓ shipped in v0.2.0 as `glint graph tree`; stages as branches, jobs as leaves, context-aware annotations
 - ~~**`glint graph includes` shows jobs per file**~~ — ✓ shipped post-v0.2.0; each include node shows the jobs it defines as dashed-arrow rounded nodes in a distinct style
-- **Multi-job connector accuracy** — draw one connector per job pair rather than one per stage pair in classic mode, so pipelines with uneven columns look correct
+- ~~**Multi-job connector accuracy**~~ — ✓ shipped v0.2.25; classic mode uses a bus-bar pattern (vertical rail at the midpoint + horizontal stubs per job) instead of a single center-to-center line, so uneven columns look correct
-- **Job tooltip / detail panel** — embed a hidden `<title>` and `<desc>` per chip so SVG viewers show `stage`, `when`, `image`, and `needs` on hover
+- ~~**Job tooltip / detail panel**~~ — ✓ shipped v0.2.25; each chip is wrapped in `<g data-job="…"><title>…</title><desc>…</desc>` — SVG viewers show stage, when, image, and needs on hover; HTML output uses the data for the sidebar
-- **`when: on_failure` visual distinction** — dashed border or distinct icon for failure-path jobs
+- ~~**`when: on_failure` visual distinction**~~ — ✓ shipped v0.2.25; dashed chip border + X-mark icon + red circle (`#d9534f`); legend entry added; Mermaid `on_failure` class wired
-- **Blocked / skipped state colouring** — grey out jobs that are statically unreachable given known `rules:` conditions
+- ~~**Blocked / skipped state colouring**~~ — ✓ shipped v0.2.25; `glint graph pipeline` accepts context flags (`--branch`, `--tag`, etc.); jobs evaluated as skipped are greyed out (`#868686`) with dimmed text and no icon
-- **Interactive HTML output** — self-contained `.html` file with pan/zoom and a job-detail sidebar; no external dependencies
+- ~~**Interactive HTML output**~~ — ✓ shipped v0.2.25; `glint graph pipeline --format html` writes a self-contained `.html` file with mouse pan/zoom and a click-to-open job-detail sidebar; no external dependencies
-- **Mermaid pipeline output** — keep `pipeline.go` but wire it up through `--graph pipeline --format mermaid` for users who want to paste into mermaid.live
+- ~~**Mermaid pipeline output**~~ — ✓ shipped v0.2.25; `glint graph pipeline --format mermaid` prints a Mermaid flowchart to stdout (paste into mermaid.live)
+- ~~**Same-stage job ordering**~~ — ✓ shipped v0.2.26; jobs within a stage that have `needs:` between each other are placed in topological sub-columns (left-to-right by depth); stage header spans all sub-columns
+- ~~**Graph links rendered behind job chips**~~ — ✓ shipped v0.2.26; SVG connectors (Bézier curves and bus-bar stubs) are drawn before job chips so lines pass behind rectangles
 
 ---
 
@@ -113,9 +115,9 @@ The SVG renderer and terminal tree cover the basic layout. These would bring it
 
 ## Reliability and developer experience
 
-- ~~**Structured rule IDs**~~ — ✓ shipped post-v0.2.0; GL001–GL031 assigned; GL032 added v0.2.11; GL033 added v0.2.15; GL034–GL041 added v0.2.16; output formats (--format json/sarif/junit/github) added v0.2.18; GL042–GL043 added v0.2.20; GL044 added v0.2.24
+- ~~**Structured rule IDs**~~ — ✓ shipped post-v0.2.0; GL001–GL031 assigned; GL032 added v0.2.11; GL033 added v0.2.15; GL034–GL041 added v0.2.16; output formats (--format json/sarif/junit/github) added v0.2.18; GL042–GL043 added v0.2.20; GL044 added v0.2.24; graph improvements shipped v0.2.25–v0.2.26
 - ~~**`glint explain <rule-id>`**~~ — ✓ shipped v0.2.20; prints rule description, rationale, bad-YAML example, and fix; `glint explain` (no arg) lists all rules
 - ~~**Semantic versioning and first release**~~ — shipped as `v0.1.0` (2026-06-07)
 - ~~**Subcommand CLI**~~ — shipped as `v0.2.0` (2026-06-11); `glint check` / `glint graph [mode]` with ruff-style `--help`
-- **Changelog automation** — generate release notes from Conventional Commits via `git-cliff` or similar
+- ~~**Changelog automation**~~ — ✓ shipped v0.2.27; `cliff.toml` configures git-cliff to produce Keep-a-Changelog–compatible release notes from Conventional Commits; `task changelog` regenerates `CHANGELOG.md`, `task changelog-next` previews unreleased entries
-- **Fuzz testing** — add a `go test -fuzz` target for the YAML parser to harden it against malformed input
+- ~~**Fuzz testing**~~ — ✓ shipped v0.2.27; `FuzzParseBytes` and `FuzzSanitizeYAMLEscapes` in `internal/model/fuzz_test.go`; seeds run as regular tests in CI; `task fuzz` runs them continuously (default 30 s)

Taskfile.yml

@@ -175,6 +175,20 @@ tasks:
     generates:
       - "{{.BINARY}}-{{.TAG}}-linux-amd64"
 
+  fuzz:
+    desc: "Run fuzz tests for the YAML parser and sanitizer (set FUZZ_TIME=60s to control duration, default 30s)"
+    cmds:
+      - "{{.GO}} test -fuzz=FuzzParseBytes          -fuzztime=${FUZZ_TIME:-30s} ./internal/model/"
+      - "{{.GO}} test -fuzz=FuzzSanitizeYAMLEscapes -fuzztime=${FUZZ_TIME:-30s} ./internal/model/"
+
+  changelog:
+    desc: "Regenerate CHANGELOG.md from git history (requires git-cliff — see README)"
+    cmd: git cliff --config cliff.toml --output CHANGELOG.md
+
+  changelog-next:
+    desc: "Preview unreleased changelog entries without writing (requires git-cliff)"
+    cmd: git cliff --config cliff.toml --unreleased
+
   clean:
     desc: Remove build artifacts
     cmd: rm -f {{.BINARY}} {{.BINARY}}-*.exe {{.BINARY}}-*-linux-amd64

USAGE.md

@@ -206,7 +206,16 @@ glint graph includes .gitlab-ci.yml > includes.mmd
 glint graph pipeline .gitlab-ci.yml
 # prints the output path, e.g.: glint-out/pipeline-20260614-143022.png
 
-# Mermaid to stdout + pipeline file path to stderr
+# Pipeline graph with skipped-job colouring (grey out context-unreachable jobs)
+glint graph pipeline --branch main .gitlab-ci.yml
+
+# Interactive HTML with pan/zoom and job-detail sidebar
+glint graph pipeline --format html .gitlab-ci.yml
+
+# Mermaid flowchart of the pipeline to stdout
+glint graph pipeline --format mermaid .gitlab-ci.yml
+
+# Mermaid includes graph to stdout + pipeline SVG file path to stderr
 glint graph all .gitlab-ci.yml > includes.mmd
 
 # Custom output directory
@@ -224,6 +233,28 @@ include type: orange (main file), purple (project), green (component), blue
 
 **Pipeline graph** — GitLab CI-style SVG rendered to a timestamped file.
 Converted to PNG when `rsvg-convert`, `inkscape`, or `magick` is available.
+
+**Pipeline graph formats** (`--format`):
+
+| Flag | Output |
+|------|--------|
+| `svg` (default) | Write SVG/PNG to `--out` |
+| `html` | Write self-contained HTML to `--out` — inline SVG with mouse pan/zoom, drag, and a job-detail sidebar that opens on chip click |
+| `mermaid` | Print Mermaid flowchart to stdout |
+
+**Visual chip styles:**
+
+| Type | Colour | Icon | Border |
+|------|--------|------|--------|
+| regular | blue `#1f75cb` | checkmark | solid |
+| manual | orange `#fc6d26` | play triangle | solid |
+| trigger | purple `#6b4fbb` | chevron | solid |
+| delayed | yellow `#fca326` | clock | solid |
+| on_failure | red `#d9534f` | X mark | dashed |
+| skipped (context) | grey `#868686` | none | solid |
+
+Pass context flags (`--branch`, `--tag`, `--source`, `--var`) to grey out jobs
+that would be skipped in the given pipeline event.
 DAG mode (Bézier arrows between jobs) activates automatically when any job has
 a `needs:` list; classic mode uses stage-column connectors otherwise.
 

cliff.toml

@@ -0,0 +1,65 @@
+# git-cliff configuration for glint
+# Install: brew install git-cliff  OR  cargo install git-cliff
+# Usage:   task changelog            -- regenerate full CHANGELOG.md
+#          task changelog-next       -- preview unreleased section (dry-run)
+
+[changelog]
+header = """
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
+This project uses [Semantic Versioning](https://semver.org).
+"""
+body = """
+{% if version %}\
+## [{{ version | trim_start_matches(pat="v") }}] - {{ timestamp | date(format="%Y-%m-%d") }}
+
+{% else %}\
+## [Unreleased]
+
+{% endif %}\
+{% for group, commits in commits | group_by(attribute="group") %}\
+### {{ group | upper_first }}
+
+{% for commit in commits %}\
+- {% if commit.scope %}**{{ commit.scope }}**: {% endif %}\
+{{ commit.message | upper_first }}\
+{% if commit.breaking %} **[BREAKING]**{% endif %}
+
+{% endfor %}\
+{% endfor %}\
+"""
+trim = true
+footer = ""
+postprocessors = []
+
+[git]
+conventional_commits = true
+filter_unconventional = true
+split_commits = false
+commit_preprocessors = [
+  # Drop Co-Authored-By trailers (should not appear in subjects, but guard anyway).
+  { pattern = "Co-Authored-By:.*", replace = "" },
+]
+commit_parsers = [
+  # Breaking changes (type! or scope!) — promote above everything else.
+  { message = "^[a-z]+\\([a-z-]+\\)!:|^[a-z]+!:", group = "Breaking Changes" },
+  { message = "^feat",     group = "Added" },
+  { message = "^fix",      group = "Fixed" },
+  { message = "^perf",     group = "Changed" },
+  { message = "^refactor", group = "Changed" },
+  # Maintenance commits — omit from the changelog body.
+  { message = "^docs",   skip = true },
+  { message = "^style",  skip = true },
+  { message = "^test",   skip = true },
+  { message = "^chore",  skip = true },
+  { message = "^build",  skip = true },
+  { message = "^claude", skip = true },
+]
+protect_breaking_commits = false
+filter_commits = true
+tag_pattern = "v[0-9].*"
+topo_order = false
+sort_commits = "oldest"

cmd/glint/main.go

@@ -445,7 +445,8 @@ func cmdGraph(args []string) {
 	gitlabURL := fs.String("gitlab-url", "", "GitLab instance URL (overrides CI_SERVER_URL / GITLAB_URL)")
 	cacheDir := fs.String("cache-dir", "", "directory to cache fetched remote includes (created if needed)")
 	offline := fs.Bool("offline", false, "skip all network calls; serve only from --cache-dir")
-	out := fs.String("out", "glint-out", "output directory for Mermaid graph files (pipeline mode)")
+	out := fs.String("out", "glint-out", "output directory for rendered graph files (pipeline mode)")
+	format := fs.String("format", "svg", "pipeline output format: svg, mermaid, or html")
 	fs.Usage = func() {
 		fmt.Fprintf(os.Stderr, "glint %s\n\n", version)
 		fmt.Fprint(os.Stderr, `Visualise the pipeline as a job tree and/or Mermaid graph.
@@ -462,6 +463,15 @@ Options:
           Output directory for rendered graph files.
           Used by the pipeline and all modes only. [default: glint-out]
 
+      --format <FORMAT>
+          Output format for pipeline mode: svg (default), mermaid, or html.
+          svg:     write a GitLab CI-style SVG/PNG to --out (converted to PNG
+                   when rsvg-convert, inkscape, or magick is available).
+          mermaid: print a Mermaid flowchart to stdout (paste into mermaid.live).
+          html:    write a self-contained HTML file with pan/zoom and a
+                   job-detail sidebar to --out.
+          [default: svg] [possible values: svg, mermaid, html]
+
       --token <TOKEN>
           GitLab personal access token. Used to fetch remote project: includes
           when building the include dependency graph.
@@ -518,6 +528,8 @@ Examples:
   glint graph includes .gitlab-ci.yml > includes.mmd
   glint graph pipeline .gitlab-ci.yml
   glint graph pipeline --out /tmp/graphs .gitlab-ci.yml
+  glint graph pipeline --format mermaid .gitlab-ci.yml
+  glint graph pipeline --format html .gitlab-ci.yml
   glint graph all .gitlab-ci.yml > includes.mmd
 `)
 	}
@@ -602,16 +614,29 @@ Examples:
 	case "includes":
 		fmt.Print(graph.Includes(path, p.Include, cfg))
 	case "pipeline":
-		outPath, err := graph.RenderPipeline(p, *out)
+		switch *format {
+		case "mermaid":
+			fmt.Print(graph.Pipeline(p))
+		case "html":
+			outPath, err := graph.RenderHTML(p, *out, ctx)
 			if err != nil {
 				fmt.Fprintf(os.Stderr, "error: rendering pipeline graph: %v\n", err)
 				exit(2)
 				return
 			}
 			fmt.Println(outPath)
+		default: // "svg"
+			outPath, err := graph.RenderPipeline(p, *out, ctx)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "error: rendering pipeline graph: %v\n", err)
+				exit(2)
+				return
+			}
+			fmt.Println(outPath)
+		}
 	case "all":
 		fmt.Print(graph.Includes(path, p.Include, cfg))
-		outPath, err := graph.RenderPipeline(p, *out)
+		outPath, err := graph.RenderPipeline(p, *out, ctx)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "error: rendering pipeline graph: %v\n", err)
 			exit(2)

internal/graph/pipeline.go

@@ -27,6 +27,7 @@ func Pipeline(p *model.Pipeline) string {
 	w("    classDef manual fill:#fc6d26,stroke:#e56b1f,color:#fff")
 	w("    classDef trigger fill:#6b4fbb,stroke:#5a3fa0,color:#fff")
 	w("    classDef delayed fill:#fca326,stroke:#d98a1e,color:#333")
+	w("    classDef on_failure fill:#d9534f,stroke:#c0392b,color:#fff")
 	w("")
 
 	// Collect visible (non-template) job names; sort for stable output.
@@ -149,6 +150,8 @@ func jobClass(job model.Job) string {
 		return "manual"
 	case "delayed":
 		return "delayed"
+	case "on_failure":
+		return "on_failure"
 	}
 	return "regular"
 }

internal/graph/pipeline_test.go

@@ -105,10 +105,23 @@ func TestSanitizeID(t *testing.T) {
 func TestJobClass(t *testing.T) {
 	if jobClass(model.Job{When: "manual"}) != "manual" { t.Error("manual") }
 	if jobClass(model.Job{When: "delayed"}) != "delayed" { t.Error("delayed") }
+	if jobClass(model.Job{When: "on_failure"}) != "on_failure" { t.Error("on_failure") }
 	if jobClass(model.Job{Trigger: "x"}) != "trigger" { t.Error("trigger") }
 	if jobClass(model.Job{}) != "regular" { t.Error("regular") }
 }
 
+func TestPipeline_OnFailureClass(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"cleanup"},
+		Jobs: map[string]model.Job{
+			"cleanup-job": {Name: "cleanup-job", Stage: "cleanup", When: "on_failure"},
+		},
+	}
+	out := Pipeline(p)
+	if !strings.Contains(out, "on_failure") { t.Error("expected on_failure class") }
+	if !strings.Contains(out, "#d9534f") { t.Error("expected on_failure color in classDef") }
+}
+
 // ── needsJobName ──────────────────────────────────────────────────────────────
 
 func TestNeedsJobName(t *testing.T) {

internal/graph/render.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"git.k3nny.fr/glint/internal/cicontext"
 	"git.k3nny.fr/glint/internal/model"
 )
 
@@ -18,26 +19,129 @@ const (
 	chipW       = 178 // job chip width
 	chipH       = 34  // job chip height
 	chipGap     = 6   // vertical gap between chips in a column
-	iconCX    = 14  // status circle: x offset from chip left edge to circle centre
+	iconCX      = 14  // status circle: x offset from chip left edge to centre
 	iconR       = 7   // status circle radius (14 px diameter)
 	textLeft    = 27  // job name text: x offset from chip left edge
 	labelH      = 30  // stage-name label area height (text + bottom gap)
 	topPad      = 40  // outer top padding
 	sidePad     = 40  // outer left / right padding
 	stageGap    = 50  // horizontal gap between stage columns (connector space)
+	subStageGap = 20  // horizontal gap between sub-columns within the same stage
 	botPad      = 48  // outer bottom padding (legend lives here)
 )
 
 type svgPt struct{ x, y int }
 
+// column represents one vertical stack of job chips in the SVG.
+// A declared GitLab stage maps to one column unless jobs within it have
+// same-stage needs:, in which case it splits into topological sub-columns.
+type column struct {
+	stage string   // declared GitLab stage name
+	jobs  []string // job names in this column, topologically ordered
+}
+
+// computeColumns assigns jobs to SVG columns.
+// When jobs within the same declared stage have needs: relationships between
+// each other, the stage is split into topological sub-columns so that
+// depended-upon jobs appear to the left of the jobs that depend on them.
+func computeColumns(stages []string, byStage map[string][]string, jobs map[string]model.Job) []column {
+	var cols []column
+	for _, stage := range stages {
+		stageJobs := byStage[stage]
+		sort.Strings(stageJobs)
+		if len(stageJobs) == 0 {
+			continue
+		}
+
+		// Index same-stage membership.
+		stageSet := make(map[string]bool, len(stageJobs))
+		for _, j := range stageJobs {
+			stageSet[j] = true
+		}
+
+		// Check whether any job has a same-stage need.
+		hasIntraNeeds := false
+		outer:
+		for _, j := range stageJobs {
+			for _, need := range jobs[j].Needs {
+				if dep := needsJobName(need); dep != "" && stageSet[dep] {
+					hasIntraNeeds = true
+					break outer
+				}
+			}
+		}
+
+		if !hasIntraNeeds {
+			cols = append(cols, column{stage: stage, jobs: stageJobs})
+			continue
+		}
+
+		// Compute topological depth within the stage.
+		depth := make(map[string]int, len(stageJobs))
+		for _, j := range stageJobs {
+			depth[j] = -1
+		}
+		inProgress := make(map[string]bool, len(stageJobs))
+		var computeDepth func(j string) int
+		computeDepth = func(j string) int {
+			if depth[j] >= 0 {
+				return depth[j]
+			}
+			if inProgress[j] {
+				return 0 // cycle guard (cycles already rejected by GL029)
+			}
+			inProgress[j] = true
+			maxDep := -1
+			for _, need := range jobs[j].Needs {
+				dep := needsJobName(need)
+				if dep == "" || !stageSet[dep] {
+					continue
+				}
+				d := computeDepth(dep)
+				if d > maxDep {
+					maxDep = d
+				}
+			}
+			depth[j] = maxDep + 1
+			return depth[j]
+		}
+		for _, j := range stageJobs {
+			if depth[j] < 0 {
+				computeDepth(j)
+			}
+		}
+
+		// One sub-column per topological depth level.
+		maxDepth := 0
+		for _, j := range stageJobs {
+			if depth[j] > maxDepth {
+				maxDepth = depth[j]
+			}
+		}
+		for l := 0; l <= maxDepth; l++ {
+			var levelJobs []string
+			for _, j := range stageJobs {
+				if depth[j] == l {
+					levelJobs = append(levelJobs, j)
+				}
+			}
+			if len(levelJobs) > 0 {
+				sort.Strings(levelJobs)
+				cols = append(cols, column{stage: stage, jobs: levelJobs})
+			}
+		}
+	}
+	return cols
+}
+
 // RenderPipeline writes a PNG (or SVG fallback) file with a GitLab CI-style
 // pipeline layout and returns the path to the generated file.
-func RenderPipeline(p *model.Pipeline, outDir string) (string, error) {
+func RenderPipeline(p *model.Pipeline, outDir string, ctx *cicontext.Context) (string, error) {
 	if err := os.MkdirAll(outDir, 0o755); err != nil {
 		return "", fmt.Errorf("creating output directory %s: %w", outDir, err)
 	}
 
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, ctx)
 
 	ts := time.Now().Format("20060102-150405")
 	svgPath := filepath.Join(outDir, "pipeline-"+ts+".svg")
@@ -53,6 +157,24 @@ func RenderPipeline(p *model.Pipeline, outDir string) (string, error) {
 	return svgPath, nil
 }
 
+// RenderHTML writes a self-contained HTML file with the pipeline graph embedded
+// inline with pan/zoom and a job-detail sidebar, then returns the output path.
+func RenderHTML(p *model.Pipeline, outDir string, ctx *cicontext.Context) (string, error) {
+	if err := os.MkdirAll(outDir, 0o755); err != nil {
+		return "", fmt.Errorf("creating output directory %s: %w", outDir, err)
+	}
+
+	svg := pipelineSVG(p, ctx)
+	html := htmlPage(svg)
+
+	ts := time.Now().Format("20060102-150405")
+	htmlPath := filepath.Join(outDir, "pipeline-"+ts+".html")
+	if err := os.WriteFile(htmlPath, []byte(html), 0o644); err != nil {
+		return "", fmt.Errorf("writing HTML: %w", err)
+	}
+	return htmlPath, nil
+}
+
 // convertToPNG tries rsvg-convert, Inkscape, magick, and convert (not on Windows).
 func convertToPNG(svgPath, pngPath string) bool {
 	candidates := [][]string{
@@ -75,7 +197,7 @@ func convertToPNG(svgPath, pngPath string) bool {
 	return false
 }
 
-func pipelineSVG(p *model.Pipeline) string {
+func pipelineSVG(p *model.Pipeline, ctx *cicontext.Context) string {
 	// Collect visible (non-template) job names in sorted order.
 	var visible []string
 	for name := range p.Jobs {
@@ -89,6 +211,16 @@ func pipelineSVG(p *model.Pipeline) string {
 		return svgEmpty()
 	}
 
+	// Precompute which jobs are skipped in the given context.
+	skippedJobs := make(map[string]bool)
+	if ctx != nil {
+		for _, name := range visible {
+			if cicontext.EvalJob(p.Jobs[name], ctx) == cicontext.JobSkipped {
+				skippedJobs[name] = true
+			}
+		}
+	}
+
 	// Group by stage; fall back to "test" (GitLab default) when stage is unset.
 	byStage := make(map[string][]string)
 	for _, name := range visible {
@@ -119,32 +251,42 @@ func pipelineSVG(p *model.Pipeline) string {
 		}
 	}
 
-	// Compute per-stage column heights and job anchor points for connectors.
+	// ── Column layout ─────────────────────────────────────────────────────────
-	colH := make([]int, len(stages))   // height of the chip stack (no label)
+	// Split stages into sub-columns when intra-stage needs exist.
-	colCtY := make([]int, len(stages)) // y centre of the chip stack
+	cols := computeColumns(stages, byStage, p.Jobs)
+
+	// X position of each column's left edge.
+	colX := make([]int, len(cols))
+	if len(cols) > 0 {
+		colX[0] = sidePad
+		for i := 1; i < len(cols); i++ {
+			gap := stageGap
+			if cols[i].stage == cols[i-1].stage {
+				gap = subStageGap
+			}
+			colX[i] = colX[i-1] + chipW + gap
+		}
+	}
+
+	// Compute SVG dimensions and per-job connector anchor points.
 	maxColH := 0
 	rightMid := make(map[string]svgPt)
 	leftMid := make(map[string]svgPt)
 
-	for i, stage := range stages {
+	for ci, col := range cols {
-		jobs := byStage[stage]
+		n := len(col.jobs)
-		sort.Strings(jobs)
-		n := len(jobs)
 		h := n*chipH + max(0, n-1)*chipGap
-		colH[i] = h
 		if h > maxColH {
 			maxColH = h
 		}
-		cx := sidePad + i*(chipW+stageGap)
+		for j, name := range col.jobs {
-		for j, name := range jobs {
 			chy := topPad + labelH + j*(chipH+chipGap)
-			rightMid[name] = svgPt{cx + chipW, chy + chipH/2}
+			rightMid[name] = svgPt{colX[ci] + chipW, chy + chipH/2}
-			leftMid[name] = svgPt{cx, chy + chipH/2}
+			leftMid[name] = svgPt{colX[ci], chy + chipH/2}
 		}
-		colCtY[i] = topPad + labelH + h/2
 	}
 
-	svgW := sidePad*2 + len(stages)*chipW + max(0, len(stages)-1)*stageGap
+	svgW := colX[len(cols)-1] + chipW + sidePad
 	svgH := topPad + labelH + maxColH + botPad
 
 	// DAG mode: any visible job with a needs: list triggers job-to-job arrows.
@@ -174,49 +316,35 @@ func pipelineSVG(p *model.Pipeline) string {
 	// White page background.
 	wf(`  <rect width="%d" height="%d" fill="#ffffff"/>`, svgW, svgH)
 
-	// ── Stage columns ─────────────────────────────────────────────────────────
+	// ── Stage headers ─────────────────────────────────────────────────────────
-	for i, stage := range stages {
+	// Each declared stage may span multiple sub-columns; draw one header per stage.
-		cx := sidePad + i*(chipW+stageGap)
+	drawnHeader := make(map[string]bool)
-		jobs := byStage[stage]
+	for ci, col := range cols {
-		sort.Strings(jobs)
+		if drawnHeader[col.stage] {
+			continue
+		}
+		// Span all sub-columns that belong to this stage.
+		x1 := colX[ci]
+		x2 := colX[ci] + chipW
+		for j := ci + 1; j < len(cols) && cols[j].stage == col.stage; j++ {
+			x2 = colX[j] + chipW
+		}
+		centerX := (x1 + x2) / 2
 
-		// Stage name – small, gray, uppercase, centered above the chip stack.
+		// Stage name – small, gray, uppercase.
 		wf(`  <text x="%d" y="%d" text-anchor="middle" `+
 			`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
 			`font-size="11" font-weight="600" letter-spacing="0.8" fill="#868686">%s</text>`,
-			cx+chipW/2, topPad+13, svgEsc(strings.ToUpper(stage)))
+			centerX, topPad+13, svgEsc(strings.ToUpper(col.stage)))
 
-		// Subtle separator line below stage name.
+		// Separator line spanning all sub-columns.
 		wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="#eaeaea" stroke-width="1"/>`,
-			cx, topPad+21, cx+chipW, topPad+21)
+			x1, topPad+21, x2, topPad+21)
 
-		// Job chips.
+		drawnHeader[col.stage] = true
-		for j, name := range jobs {
-			job := p.Jobs[name]
-			chy := topPad + labelH + j*(chipH+chipGap)
-			color := chipColor(job)
-
-			// Chip card (white, rounded, subtle border + shadow).
-			wf(`  <rect x="%d" y="%d" width="%d" height="%d" rx="4" `+
-				`fill="#ffffff" stroke="#dde1e7" stroke-width="1" filter="url(#chip-shadow)"/>`,
-				cx, chy, chipW, chipH)
-
-			// Colored status indicator circle.
-			wf(`  <circle cx="%d" cy="%d" r="%d" fill="%s"/>`,
-				cx+iconCX, chy+chipH/2, iconR, color)
-
-			// Icon symbol inside the circle.
-			drawChipIcon(&sb, job, cx+iconCX, chy+chipH/2)
-
-			// Job name text.
-			wf(`  <text x="%d" y="%d" dominant-baseline="middle" `+
-				`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
-				`font-size="13" fill="#303030">%s</text>`,
-				cx+textLeft, chy+chipH/2, svgEsc(svgTrunc(name, 20)))
-		}
 	}
 
-	// ── Connectors ────────────────────────────────────────────────────────────
+	// ── Connectors (drawn before chips so they appear behind job blocks) ───────
 	const connStroke = "#dbdbdb"
 
 	if dagMode {
@@ -241,27 +369,123 @@ func pipelineSVG(p *model.Pipeline) string {
 			}
 		}
 	} else {
-		// Classic: one connector per adjacent stage pair.
+		// Classic: bus-bar connectors between adjacent stage columns.
-		for i := 0; i < len(stages)-1; i++ {
+		// Every job in stage[i] fans to a vertical bus at the midpoint gap,
-			x1 := sidePad + i*(chipW+stageGap) + chipW
+		// then fans out to every job in stage[i+1].
-			x2 := sidePad + (i+1)*(chipW+stageGap)
+		for ci := 0; ci < len(cols)-1; ci++ {
-			y1 := colCtY[i]
+			x1 := colX[ci] + chipW    // right edge of current column
-			y2 := colCtY[i+1]
+			x2 := colX[ci+1]          // left edge of next column
 			midX := (x1 + x2) / 2
 
-			if y1 == y2 {
+			srcJobs := cols[ci].jobs
-				// Straight horizontal line.
+			dstJobs := cols[ci+1].jobs
-				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+
-					x1, y1, x2-7, y2, connStroke)
+			// Collect all Y midpoints to span the vertical bus bar.
-			} else {
+			var allYs []int
-				// L-shaped elbow: right → vertical → right.
+			srcY := make([]int, len(srcJobs))
-				wf(`  <polyline points="%d,%d %d,%d %d,%d %d,%d" `+
+			dstY := make([]int, len(dstJobs))
-					`stroke="%s" stroke-width="2" fill="none" stroke-linejoin="round"/>`,
+			for j, name := range srcJobs {
-					x1, y1, midX, y1, midX, y2, x2-7, y2, connStroke)
+				srcY[j] = rightMid[name].y
+				allYs = append(allYs, srcY[j])
 			}
-			// Arrowhead at the destination.
+			for j, name := range dstJobs {
+				dstY[j] = leftMid[name].y
+				allYs = append(allYs, dstY[j])
+			}
+			sort.Ints(allYs)
+			busMinY, busMaxY := allYs[0], allYs[len(allYs)-1]
+
+			// Vertical bus bar at midX (only when there are multiple Y levels).
+			if busMinY < busMaxY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					midX, busMinY, midX, busMaxY, connStroke)
+			}
+
+			// Horizontal stubs from each source job to the bus.
+			for _, y := range srcY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					x1, y, midX, y, connStroke)
+			}
+
+			// Horizontal stubs from bus to each destination job, with arrowhead.
+			for _, y := range dstY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					midX, y, x2-7, y, connStroke)
 				wf(`  <polygon points="%d,%d %d,%d %d,%d" fill="%s"/>`,
-				x2-7, y2-4, x2, y2, x2-7, y2+4, connStroke)
+					x2-7, y-4, x2, y, x2-7, y+4, connStroke)
+			}
+		}
+	}
+
+	// ── Job chips (drawn after connectors so they appear on top) ─────────────
+	for ci, col := range cols {
+		for j, name := range col.jobs {
+			job := p.Jobs[name]
+			chy := topPad + labelH + j*(chipH+chipGap)
+			isSkipped := skippedJobs[name]
+			cx := colX[ci]
+
+			// Build <desc> content: shown in the HTML sidebar and SVG viewer tooltips.
+			desc := "stage: " + col.stage
+			if job.When != "" {
+				desc += "\nwhen: " + job.When
+			}
+			if img := imageString(job.Image); img != "" {
+				desc += "\nimage: " + img
+			}
+			var needNames []string
+			for _, n := range job.Needs {
+				if s := needsJobName(n); s != "" {
+					needNames = append(needNames, s)
+				}
+			}
+			if len(needNames) > 0 {
+				desc += "\nneeds: " + strings.Join(needNames, ", ")
+			}
+			if isSkipped {
+				desc += "\nstate: skipped"
+			}
+
+			// data-job attribute enables JS click detection in the HTML output.
+			wf(`  <g data-job="%s">`, svgEsc(name))
+			wf(`    <title>%s</title>`, svgEsc(name))
+			wf(`    <desc>%s</desc>`, svgEsc(desc))
+
+			color := chipColor(job)
+			if isSkipped {
+				color = "#868686"
+			}
+
+			// Chip card (white, rounded, subtle border + shadow).
+			// on_failure jobs get a dashed border to signal the failure path.
+			dashAttr := ""
+			if !isSkipped && job.When == "on_failure" {
+				dashAttr = ` stroke-dasharray="4,3"`
+			}
+			wf(`    <rect x="%d" y="%d" width="%d" height="%d" rx="4" `+
+				`fill="#ffffff" stroke="#dde1e7" stroke-width="1"%s filter="url(#chip-shadow)"/>`,
+				cx, chy, chipW, chipH, dashAttr)
+
+			// Colored status indicator circle.
+			wf(`    <circle cx="%d" cy="%d" r="%d" fill="%s"/>`,
+				cx+iconCX, chy+chipH/2, iconR, color)
+
+			// Icon inside the circle (omitted for skipped — grey circle speaks for itself).
+			if !isSkipped {
+				drawChipIcon(&sb, job, cx+iconCX, chy+chipH/2)
+			}
+
+			// Job name text — dimmed for skipped jobs.
+			textColor := "#303030"
+			if isSkipped {
+				textColor = "#868686"
+			}
+			wf(`    <text x="%d" y="%d" dominant-baseline="middle" `+
+				`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
+				`font-size="13" fill="%s">%s</text>`,
+				cx+textLeft, chy+chipH/2, textColor, svgEsc(svgTrunc(name, 20)))
+
+			wf(`  </g>`)
 		}
 	}
 
@@ -271,6 +495,7 @@ func pipelineSVG(p *model.Pipeline) string {
 		{"#fc6d26", "manual"},
 		{"#6b4fbb", "trigger"},
 		{"#fca326", "delayed"},
+		{"#d9534f", "on_failure"},
 	}
 	const legendItemW = 82
 	legendY := topPad + labelH + maxColH + botPad/2
@@ -304,14 +529,20 @@ func drawChipIcon(sb *strings.Builder, job model.Job, cx, cy int) {
 		fmt.Fprintf(sb, "    <polygon points=\"%d,%d %d,%d %d,%d\" fill=\"#fff\"/>\n",
 			cx-3, cy-4, cx+5, cy, cx-3, cy+4)
 	case "delayed":
-		// Clock hands: vertical + horizontal.
+		// Clock: circle + hands.
 		fmt.Fprintf(sb, "    <circle cx=\"%d\" cy=\"%d\" r=\"5\" stroke=\"#fff\" stroke-width=\"1.2\" fill=\"none\"/>\n", cx, cy)
 		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
 			cx, cy, cx, cy-3)
 		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
 			cx, cy, cx+2, cy+1)
+	case "on_failure":
+		// X mark for failure-path jobs.
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>\n",
+			cx-3, cy-3, cx+3, cy+3)
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>\n",
+			cx+3, cy-3, cx-3, cy+3)
 	default:
-		// Regular job: small white checkmark outline.
+		// Regular job: small white checkmark.
 		fmt.Fprintf(sb, "    <polyline points=\"%d,%d %d,%d %d,%d\" "+
 			"stroke=\"#fff\" stroke-width=\"1.5\" fill=\"none\" stroke-linecap=\"round\" stroke-linejoin=\"round\"/>\n",
 			cx-3, cy, cx-1, cy+3, cx+4, cy-3)
@@ -327,10 +558,25 @@ func chipColor(job model.Job) string {
 		return "#fc6d26"
 	case "delayed":
 		return "#fca326"
+	case "on_failure":
+		return "#d9534f"
 	}
 	return "#1f75cb"
 }
 
+// imageString extracts the image name from a job Image field (string or map form).
+func imageString(img any) string {
+	switch v := img.(type) {
+	case string:
+		return v
+	case map[string]any:
+		if name, ok := v["name"].(string); ok {
+			return name
+		}
+	}
+	return ""
+}
+
 func svgEsc(s string) string {
 	s = strings.ReplaceAll(s, "&", "&amp;")
 	s = strings.ReplaceAll(s, "<", "&lt;")
@@ -356,3 +602,179 @@ func svgEmpty() string {
 			`</svg>`,
 		w, h, w, h, w/2, h/2)
 }
+
+// htmlPage wraps an SVG pipeline graph in a self-contained HTML page with
+// mouse pan/zoom and a job-detail sidebar that appears on chip click.
+func htmlPage(svgContent string) string {
+	var sb strings.Builder
+	sb.WriteString(`<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<title>Pipeline Graph</title>
+<style>
+*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+body {
+  font-family: 'Segoe UI', Arial, sans-serif;
+  background: #f5f5f5;
+  display: flex;
+  height: 100vh;
+  overflow: hidden;
+}
+#sidebar {
+  width: 260px;
+  flex-shrink: 0;
+  background: #fff;
+  border-right: 1px solid #e0e0e0;
+  display: none;
+  flex-direction: column;
+  overflow-y: auto;
+}
+#sidebar.open { display: flex; }
+#sidebar-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: .6rem .8rem;
+  border-bottom: 1px solid #e0e0e0;
+  background: #fafafa;
+  flex-shrink: 0;
+}
+#sidebar-header h3 {
+  font-size: .9rem;
+  color: #303030;
+  word-break: break-all;
+}
+#close-btn {
+  background: none;
+  border: none;
+  cursor: pointer;
+  font-size: 1rem;
+  color: #868686;
+  padding: .2rem .4rem;
+  margin-left: .4rem;
+  flex-shrink: 0;
+}
+#close-btn:hover { color: #303030; }
+#sidebar-body { padding: .8rem; flex: 1; }
+#sidebar-body pre {
+  font-size: .82rem;
+  color: #555;
+  white-space: pre-wrap;
+  line-height: 1.6;
+}
+#viewport {
+  flex: 1;
+  overflow: hidden;
+  cursor: grab;
+  position: relative;
+  background: #f5f5f5;
+}
+#viewport.dragging { cursor: grabbing; }
+#svg-wrap {
+  display: inline-block;
+  transform-origin: 0 0;
+  padding: 20px;
+}
+g[data-job] { cursor: pointer; }
+g[data-job]:hover > rect { stroke: #1f75cb; stroke-width: 2; }
+</style>
+</head>
+<body>
+<div id="sidebar">
+  <div id="sidebar-header">
+    <h3 id="sidebar-title">Job details</h3>
+    <button id="close-btn" title="Close">&#x2715;</button>
+  </div>
+  <div id="sidebar-body">
+    <pre id="sidebar-details"></pre>
+  </div>
+</div>
+<div id="viewport">
+  <div id="svg-wrap">
+`)
+	sb.WriteString(svgContent)
+	sb.WriteString(`
+  </div>
+</div>
+<script>
+(function() {
+  'use strict';
+  var vp = document.getElementById('viewport');
+  var wrap = document.getElementById('svg-wrap');
+  var sidebar = document.getElementById('sidebar');
+  var titleEl = document.getElementById('sidebar-title');
+  var detailsEl = document.getElementById('sidebar-details');
+  var tx = 0, ty = 0, scale = 1;
+
+  function applyTransform() {
+    wrap.style.transform = 'translate(' + tx + 'px,' + ty + 'px) scale(' + scale + ')';
+  }
+
+  // Zoom toward the cursor position.
+  vp.addEventListener('wheel', function(e) {
+    e.preventDefault();
+    var factor = e.deltaY < 0 ? 1.1 : 1 / 1.1;
+    var r = vp.getBoundingClientRect();
+    var mx = e.clientX - r.left;
+    var my = e.clientY - r.top;
+    tx = mx - (mx - tx) * factor;
+    ty = my - (my - ty) * factor;
+    scale *= factor;
+    applyTransform();
+  }, { passive: false });
+
+  // Drag to pan (skip if clicking on a job chip).
+  var dragging = false, ox = 0, oy = 0;
+  vp.addEventListener('mousedown', function(e) {
+    if (e.target.closest('g[data-job]')) return;
+    dragging = true;
+    ox = e.clientX - tx;
+    oy = e.clientY - ty;
+    vp.classList.add('dragging');
+  });
+  window.addEventListener('mousemove', function(e) {
+    if (!dragging) return;
+    tx = e.clientX - ox;
+    ty = e.clientY - oy;
+    applyTransform();
+  });
+  window.addEventListener('mouseup', function() {
+    dragging = false;
+    vp.classList.remove('dragging');
+  });
+
+  // Double-click on the background to reset the view.
+  vp.addEventListener('dblclick', function(e) {
+    if (e.target.closest('g[data-job]')) return;
+    tx = 0; ty = 0; scale = 1;
+    applyTransform();
+  });
+
+  // Click a job chip to show its details in the sidebar.
+  document.addEventListener('click', function(e) {
+    var g = e.target.closest('g[data-job]');
+    if (!g) return;
+    var jobName = g.dataset.job;
+    var descEl = g.querySelector('desc');
+    var desc = descEl ? descEl.textContent : '';
+    titleEl.textContent = jobName;
+    detailsEl.textContent = desc;
+    sidebar.classList.add('open');
+  });
+
+  // Close the sidebar.
+  document.getElementById('close-btn').addEventListener('click', function() {
+    sidebar.classList.remove('open');
+  });
+  document.addEventListener('keydown', function(e) {
+    if (e.key === 'Escape') sidebar.classList.remove('open');
+  });
+})();
+</script>
+</body>
+</html>
+`)
+	return sb.String()
+}

internal/graph/render_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 
+	"git.k3nny.fr/glint/internal/cicontext"
 	"git.k3nny.fr/glint/internal/model"
 )
 
@@ -59,9 +60,20 @@ func TestChipColor(t *testing.T) {
 	if chipColor(model.Job{Trigger: "x"}) != "#6b4fbb" { t.Error("trigger color") }
 	if chipColor(model.Job{When: "manual"}) != "#fc6d26" { t.Error("manual color") }
 	if chipColor(model.Job{When: "delayed"}) != "#fca326" { t.Error("delayed color") }
+	if chipColor(model.Job{When: "on_failure"}) != "#d9534f" { t.Error("on_failure color") }
 	if chipColor(model.Job{}) != "#1f75cb" { t.Error("regular color") }
 }
 
+// ── imageString ───────────────────────────────────────────────────────────────
+
+func TestImageString(t *testing.T) {
+	if imageString("alpine") != "alpine" { t.Error("string form") }
+	if imageString(map[string]any{"name": "golang:1.21"}) != "golang:1.21" { t.Error("map form") }
+	if imageString(map[string]any{"other": "x"}) != "" { t.Error("map without name key") }
+	if imageString(nil) != "" { t.Error("nil") }
+	if imageString(42) != "" { t.Error("unexpected type") }
+}
+
 // ── drawChipIcon ──────────────────────────────────────────────────────────────
 
 func TestDrawChipIcon(t *testing.T) {
@@ -72,6 +84,7 @@ func TestDrawChipIcon(t *testing.T) {
 		{model.Job{Trigger: "x"}, "<polyline"},
 		{model.Job{When: "manual"}, "<polygon"},
 		{model.Job{When: "delayed"}, "<circle"},
+		{model.Job{When: "on_failure"}, "<line"},
 		{model.Job{}, "<polyline"},
 	}
 	for _, tc := range cases {
@@ -86,7 +99,7 @@ func TestDrawChipIcon(t *testing.T) {
 // ── pipelineSVG ───────────────────────────────────────────────────────────────
 
 func TestPipelineSVG_Empty(t *testing.T) {
-	svg := pipelineSVG(&model.Pipeline{})
+	svg := pipelineSVG(&model.Pipeline{}, nil)
 	if !strings.Contains(svg, "no jobs defined") {
 		t.Errorf("expected 'no jobs defined', got:\n%s", svg)
 	}
@@ -100,13 +113,32 @@ func TestPipelineSVG_ClassicMode(t *testing.T) {
 			"test-job":  {Name: "test-job", Stage: "test"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 	if !strings.Contains(svg, "build-job") { t.Error("expected build-job") }
 	if !strings.Contains(svg, "test-job") { t.Error("expected test-job") }
-	// Classic mode connector
+	// Classic mode bus-bar draws <line> elements for connectors
-	if !strings.Contains(svg, "<polyline") && !strings.Contains(svg, "<line") {
+	if !strings.Contains(svg, "<line") {
-		t.Error("expected connector in classic mode")
+		t.Error("expected <line> connector in classic mode")
+	}
+}
+
+func TestPipelineSVG_ClassicMode_MultiJob(t *testing.T) {
+	// Two source jobs, two destination jobs → bus-bar with vertical segment
+	p := &model.Pipeline{
+		Stages: []string{"build", "test"},
+		Jobs: map[string]model.Job{
+			"build-a": {Name: "build-a", Stage: "build"},
+			"build-b": {Name: "build-b", Stage: "build"},
+			"test-a":  {Name: "test-a", Stage: "test"},
+			"test-b":  {Name: "test-b", Stage: "test"},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	// Bus bar: horizontal stubs from each src + dst, plus a vertical bus line
+	// and an arrowhead polygon for each dst job.
+	if !strings.Contains(svg, "<polygon") {
+		t.Error("expected arrowhead <polygon> in multi-job classic mode")
 	}
 }
 
@@ -118,7 +150,7 @@ func TestPipelineSVG_DAGMode(t *testing.T) {
 			"test-job":  {Name: "test-job", Stage: "test", Needs: []any{"build-job"}},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	// DAG mode draws <path> bezier curves
 	if !strings.Contains(svg, "<path") {
 		t.Error("expected <path> connector in DAG mode")
@@ -126,7 +158,7 @@ func TestPipelineSVG_DAGMode(t *testing.T) {
 }
 
 func TestPipelineSVG_DAGMode_StraightConnector(t *testing.T) {
-	// Two stages at same height → straight <line> connector in classic mode
+	// Two stages at same height → straight connector in classic mode
 	p := &model.Pipeline{
 		Stages: []string{"a", "b"},
 		Jobs: map[string]model.Job{
@@ -134,7 +166,7 @@ func TestPipelineSVG_DAGMode_StraightConnector(t *testing.T) {
 			"j2": {Name: "j2", Stage: "b"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 }
 
@@ -145,13 +177,18 @@ func TestPipelineSVG_AllJobTypes(t *testing.T) {
 			"manual-job":     {Name: "manual-job", Stage: "deploy", When: "manual"},
 			"delayed-job":    {Name: "delayed-job", Stage: "deploy", When: "delayed"},
 			"trigger-job":    {Name: "trigger-job", Stage: "deploy", Trigger: "other/project"},
+			"onfailure-job":  {Name: "onfailure-job", Stage: "deploy", When: "on_failure"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
-	// Each type has its own color in the SVG
 	if !strings.Contains(svg, "#fc6d26") { t.Error("expected manual color") }
 	if !strings.Contains(svg, "#fca326") { t.Error("expected delayed color") }
 	if !strings.Contains(svg, "#6b4fbb") { t.Error("expected trigger color") }
+	if !strings.Contains(svg, "#d9534f") { t.Error("expected on_failure color") }
+	// on_failure chips have a dashed border
+	if !strings.Contains(svg, `stroke-dasharray="4,3"`) {
+		t.Error("expected dashed border on on_failure chip")
+	}
 }
 
 func TestPipelineSVG_JobNoStage(t *testing.T) {
@@ -160,7 +197,7 @@ func TestPipelineSVG_JobNoStage(t *testing.T) {
 			"myjob": {Name: "myjob"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "myjob") { t.Error("expected myjob") }
 }
 
@@ -172,10 +209,85 @@ func TestPipelineSVG_CrossPipelineNeed(t *testing.T) {
 				Needs: []any{map[string]any{"pipeline": "other", "job": "x"}}},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 }
 
+func TestPipelineSVG_Tooltip(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"build-job": {
+				Name:  "build-job",
+				Stage: "build",
+				When:  "on_success",
+				Image: "golang:1.21",
+				Needs: []any{"prep-job"},
+			},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	// Tooltip <title> and <desc> should appear inside the <g data-job> wrapper
+	if !strings.Contains(svg, `<title>build-job</title>`) {
+		t.Error("expected <title>build-job</title>")
+	}
+	if !strings.Contains(svg, `<desc>`) {
+		t.Error("expected <desc> element")
+	}
+	if !strings.Contains(svg, "image: golang:1.21") {
+		t.Error("expected image in desc")
+	}
+	if !strings.Contains(svg, "needs: prep-job") {
+		t.Error("expected needs in desc")
+	}
+	if !strings.Contains(svg, `data-job="build-job"`) {
+		t.Error("expected data-job attribute")
+	}
+}
+
+func TestPipelineSVG_SkippedJob(t *testing.T) {
+	// A job with rules that never match in the given context should be greyed out.
+	p := &model.Pipeline{
+		Stages: []string{"deploy"},
+		Jobs: map[string]model.Job{
+			"deploy-job": {
+				Name:   "deploy-job",
+				Stage:  "deploy",
+				Script: []any{"deploy.sh"},
+				Rules: []model.Rule{
+					{If: `$CI_COMMIT_TAG != ""`, When: "on_success"},
+				},
+			},
+		},
+	}
+	// Branch context: CI_COMMIT_TAG is empty → rule doesn't match → job skipped
+	ctx := cicontext.New("main", "", "push", nil)
+	svg := pipelineSVG(p, ctx)
+
+	// Skipped jobs use grey (#868686) instead of the regular blue
+	if !strings.Contains(svg, `fill="#868686"`) {
+		t.Error("expected grey fill for skipped job circle")
+	}
+	// Skipped state should appear in the tooltip desc
+	if !strings.Contains(svg, "state: skipped") {
+		t.Error("expected 'state: skipped' in tooltip desc")
+	}
+}
+
+func TestPipelineSVG_ContextNil(t *testing.T) {
+	// nil context → no skipped jobs, regular colors
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"j": {Name: "j", Stage: "build"},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	if !strings.Contains(svg, `fill="#1f75cb"`) {
+		t.Error("expected regular blue fill with nil context")
+	}
+}
+
 // ── RenderPipeline ────────────────────────────────────────────────────────────
 
 func TestRenderPipeline(t *testing.T) {
@@ -186,7 +298,7 @@ func TestRenderPipeline(t *testing.T) {
 		},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -202,7 +314,7 @@ func TestRenderPipeline_InvalidDir(t *testing.T) {
 	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	_, err := RenderPipeline(&model.Pipeline{}, filePath+"/nested")
+	_, err := RenderPipeline(&model.Pipeline{}, filePath+"/nested", nil)
 	if err == nil {
 		t.Error("expected error writing to path under a file")
 	}
@@ -222,7 +334,7 @@ func TestRenderPipeline_WriteFileFails(t *testing.T) {
 		Stages: []string{"build"},
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
-	_, err := RenderPipeline(p, dir)
+	_, err := RenderPipeline(p, dir, nil)
 	if err == nil {
 		t.Error("expected error when writing SVG to read-only directory")
 	}
@@ -241,7 +353,7 @@ func TestRenderPipeline_SVGFallback(t *testing.T) {
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -264,7 +376,7 @@ func TestConvertToPNG_NoConverter(t *testing.T) {
 
 func TestConvertToPNG_FakeConverter(t *testing.T) {
 	// Install a fake rsvg-convert that just creates the output file and exits 0.
-	// This exercises the "return true" branch (line 72) and os.Remove in RenderPipeline.
+	// This exercises the "return true" branch and os.Remove in RenderPipeline.
 	binDir := t.TempDir()
 	script := "#!/bin/sh\n# rsvg-convert --output <out> <in>\ncp \"$3\" \"$2\"\n"
 	fakeBin := binDir + "/rsvg-convert"
@@ -303,7 +415,7 @@ func TestRenderPipeline_PNGConversion(t *testing.T) {
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -315,7 +427,7 @@ func TestRenderPipeline_PNGConversion(t *testing.T) {
 // ── pipelineSVG coverage gaps ─────────────────────────────────────────────────
 
 func TestPipelineSVG_LShapedElbow(t *testing.T) {
-	// Classic mode with unequal stage sizes → different column heights → L-shaped elbow
+	// Classic mode with unequal stage sizes → vertical bus bar required
 	p := &model.Pipeline{
 		Stages: []string{"build", "test"},
 		Jobs: map[string]model.Job{
@@ -324,9 +436,10 @@ func TestPipelineSVG_LShapedElbow(t *testing.T) {
 			"j3": {Name: "j3", Stage: "test"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
-	if !strings.Contains(svg, "<polyline") {
+	// The bus bar is a <line>; arrowheads are <polygon>
-		t.Error("expected <polyline> for L-shaped elbow connector")
+	if !strings.Contains(svg, "<polygon") {
+		t.Error("expected <polygon> arrowhead in bus-bar connector")
 	}
 }
 
@@ -339,9 +452,214 @@ func TestPipelineSVG_DAGNeedNotInPositionMap(t *testing.T) {
 			".hidden-template": {Name: ".hidden-template", Stage: "build"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	// Should render without panic; .hidden-template is not visible so no connector drawn.
 	if !strings.Contains(svg, "<svg") {
 		t.Error("expected valid SVG output")
 	}
 }
+
+// ── RenderHTML ────────────────────────────────────────────────────────────────
+
+func TestRenderHTML(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"build-job": {Name: "build-job", Stage: "build"},
+		},
+	}
+	dir := t.TempDir()
+	path, err := RenderHTML(p, dir, nil)
+	if err != nil {
+		t.Fatalf("RenderHTML: %v", err)
+	}
+	if !strings.HasSuffix(path, ".html") {
+		t.Errorf("expected .html output, got %q", path)
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading output: %v", err)
+	}
+	html := string(data)
+	if !strings.Contains(html, "<!DOCTYPE html>") { t.Error("expected DOCTYPE") }
+	if !strings.Contains(html, "<svg") { t.Error("expected embedded <svg") }
+	if !strings.Contains(html, "build-job") { t.Error("expected job name in HTML") }
+	if !strings.Contains(html, "applyTransform") { t.Error("expected JS pan/zoom function") }
+	if !strings.Contains(html, "sidebar") { t.Error("expected sidebar element") }
+}
+
+func TestRenderHTML_InvalidDir(t *testing.T) {
+	dir := t.TempDir()
+	filePath := dir + "/notadir"
+	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	_, err := RenderHTML(&model.Pipeline{}, filePath+"/nested", nil)
+	if err == nil {
+		t.Error("expected error writing to path under a file")
+	}
+}
+
+func TestRenderHTML_WriteFileFails(t *testing.T) {
+	if os.Getuid() == 0 {
+		t.Skip("skipping as root — file permissions don't apply")
+	}
+	dir := t.TempDir()
+	if err := os.Chmod(dir, 0o555); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.Chmod(dir, 0o755) })
+
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
+	}
+	_, err := RenderHTML(p, dir, nil)
+	if err == nil {
+		t.Error("expected error when writing HTML to read-only directory")
+	}
+}
+
+// ── computeColumns ────────────────────────────────────────────────────────────
+
+func TestComputeColumns_NoIntraNeeds(t *testing.T) {
+	// No intra-stage needs → one column per stage.
+	stages := []string{"build", "test"}
+	byStage := map[string][]string{
+		"build": {"build-a", "build-b"},
+		"test":  {"test-a"},
+	}
+	jobs := map[string]model.Job{
+		"build-a": {Name: "build-a", Stage: "build"},
+		"build-b": {Name: "build-b", Stage: "build"},
+		"test-a":  {Name: "test-a", Stage: "test"},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 columns (one per stage), got %d", len(cols))
+	}
+	if cols[0].stage != "build" || len(cols[0].jobs) != 2 {
+		t.Errorf("col[0]: got stage=%q jobs=%v", cols[0].stage, cols[0].jobs)
+	}
+	if cols[1].stage != "test" || len(cols[1].jobs) != 1 {
+		t.Errorf("col[1]: got stage=%q jobs=%v", cols[1].stage, cols[1].jobs)
+	}
+}
+
+func TestComputeColumns_IntraNeeds(t *testing.T) {
+	// job-b depends on job-a in the same stage → split into 2 sub-columns.
+	stages := []string{"build"}
+	byStage := map[string][]string{
+		"build": {"job-a", "job-b"},
+	}
+	jobs := map[string]model.Job{
+		"job-a": {Name: "job-a", Stage: "build"},
+		"job-b": {Name: "job-b", Stage: "build", Needs: []any{"job-a"}},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 sub-columns, got %d", len(cols))
+	}
+	// Both belong to the same stage.
+	if cols[0].stage != "build" || cols[1].stage != "build" {
+		t.Error("both sub-columns should be in stage 'build'")
+	}
+	// job-a has no same-stage deps → depth 0 → first sub-column.
+	if len(cols[0].jobs) != 1 || cols[0].jobs[0] != "job-a" {
+		t.Errorf("col[0] should contain job-a, got %v", cols[0].jobs)
+	}
+	// job-b depends on job-a → depth 1 → second sub-column.
+	if len(cols[1].jobs) != 1 || cols[1].jobs[0] != "job-b" {
+		t.Errorf("col[1] should contain job-b, got %v", cols[1].jobs)
+	}
+}
+
+func TestComputeColumns_EmptyStageSkipped(t *testing.T) {
+	// Stages with no jobs are silently skipped.
+	stages := []string{"build", "empty", "test"}
+	byStage := map[string][]string{
+		"build": {"j1"},
+		"test":  {"j2"},
+	}
+	jobs := map[string]model.Job{
+		"j1": {Name: "j1", Stage: "build"},
+		"j2": {Name: "j2", Stage: "test"},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 columns (empty stage skipped), got %d", len(cols))
+	}
+}
+
+func TestComputeColumns_CrossStageNeedIgnored(t *testing.T) {
+	// job-b has needs: for both job-a (same stage) and prev-job (different stage).
+	// The cross-stage need must be ignored when computing topological depth.
+	stages := []string{"build"}
+	byStage := map[string][]string{
+		"build": {"job-a", "job-b"},
+	}
+	jobs := map[string]model.Job{
+		"job-a": {Name: "job-a", Stage: "build"},
+		"job-b": {Name: "job-b", Stage: "build", Needs: []any{"job-a", "prev-job"}},
+		"prev-job": {Name: "prev-job", Stage: "prepare"},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	// Still split into 2 sub-columns; the cross-stage need is ignored.
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 sub-columns, got %d", len(cols))
+	}
+	if cols[0].jobs[0] != "job-a" {
+		t.Errorf("expected job-a in first sub-column, got %v", cols[0].jobs)
+	}
+	if cols[1].jobs[0] != "job-b" {
+		t.Errorf("expected job-b in second sub-column, got %v", cols[1].jobs)
+	}
+}
+
+func TestComputeColumns_CycleGuard(t *testing.T) {
+	// Intra-stage cycle must not hang (cycle guard returns depth 0).
+	stages := []string{"build"}
+	byStage := map[string][]string{
+		"build": {"a", "b"},
+	}
+	jobs := map[string]model.Job{
+		"a": {Name: "a", Stage: "build", Needs: []any{"b"}},
+		"b": {Name: "b", Stage: "build", Needs: []any{"a"}},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	// Should return without hanging; exact column count is implementation-defined.
+	if len(cols) == 0 {
+		t.Error("expected at least one column")
+	}
+}
+
+func TestPipelineSVG_IntraStageDAG(t *testing.T) {
+	// job-b depends on job-a in the same stage → SVG should render both,
+	// placed as sub-columns (sub-stage gap between them).
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"job-a": {Name: "job-a", Stage: "build"},
+			"job-b": {Name: "job-b", Stage: "build", Needs: []any{"job-a"}},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	if !strings.Contains(svg, "job-a") { t.Error("expected job-a in SVG") }
+	if !strings.Contains(svg, "job-b") { t.Error("expected job-b in SVG") }
+	// DAG mode: bezier connectors between the two jobs.
+	if !strings.Contains(svg, "<path") {
+		t.Error("expected bezier <path> connector between intra-stage jobs")
+	}
+}
+
+// ── htmlPage ──────────────────────────────────────────────────────────────────
+
+func TestHtmlPage(t *testing.T) {
+	svgContent := `<svg xmlns="http://www.w3.org/2000/svg" width="100" height="50"><rect/></svg>`
+	html := htmlPage(svgContent)
+	if !strings.Contains(html, "<!DOCTYPE html>") { t.Error("expected DOCTYPE") }
+	if !strings.Contains(html, svgContent) { t.Error("expected SVG embedded in HTML") }
+	if !strings.Contains(html, "id=\"viewport\"") { t.Error("expected viewport element") }
+	if !strings.Contains(html, "id=\"sidebar\"") { t.Error("expected sidebar element") }
+	if !strings.Contains(html, "applyTransform") { t.Error("expected JS transform function") }
+}

internal/model/fuzz_test.go

@@ -0,0 +1,77 @@
+package model
+
+import "testing"
+
+// FuzzParseBytes ensures the YAML parser never panics on arbitrary input and
+// that successful parses return a structurally sound Pipeline.
+// Run with: go test -fuzz=FuzzParseBytes ./internal/model/
+// Found failures are saved to testdata/fuzz/FuzzParseBytes/.
+func FuzzParseBytes(f *testing.F) {
+	// Seed corpus: representative inputs covering the main code paths in
+	// ParseBytes, including the sanitizeYAMLEscapes pre-processing step.
+	seeds := [][]byte{
+		{},
+		[]byte("null"),
+		[]byte("stages: [build]\nbuild-job:\n  stage: build\n  script: echo ok\n"),
+		[]byte(".base:\n  script: [make]\nchild:\n  extends: .base\n  stage: test\n"),
+		[]byte("stages: [a, b]\njob-a:\n  stage: a\n  script: run\njob-b:\n  stage: b\n  needs: [job-a]\n  script: run\n"),
+		[]byte("*undefined_anchor"),
+		[]byte("- item1\n- item2\n"),
+		[]byte("my-job: \"just a string\"\n"),
+		[]byte("my-job:\n  stage: [build, test]\n"),
+		[]byte("# glint: ignore GL007\nlegacy:\n  only: [main]\n  script: ok\n"),
+		[]byte("workflow:\n  rules:\n    - if: '$CI_COMMIT_BRANCH == \"main\"'\n      when: always\njob:\n  script: echo ok\n"),
+		[]byte("include:\n  - local: other.yml\njob:\n  script: echo ok\n"),
+		[]byte("job:\n  script: echo ok\n  when: on_failure\n  rules:\n    - if: '$VAR =~ /^us\\//'\n"),
+		[]byte("job:\n  stage: test\n  image:\n    name: golang:1.21\n    entrypoint: ['']\n  parallel:\n    matrix:\n      - PLATFORM: [linux, darwin]\n  script: go build\n"),
+		[]byte("default:\n  retry: 2\n  timeout: 1h30m\nvariables:\n  ENV: production\nstages: [build, test, deploy]\n"),
+		[]byte("&anchor\n  script: [echo ok]\njob:\n  <<: *anchor\n  stage: build\n"),
+	}
+	for _, s := range seeds {
+		f.Add(s)
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		p, err := ParseBytes(data)
+		if err != nil {
+			return // errors are acceptable; panics are not
+		}
+		if p == nil {
+			t.Fatal("ParseBytes returned nil pipeline with nil error")
+		}
+		for name := range p.Jobs {
+			if name == "" {
+				t.Fatal("ParseBytes produced a job with an empty name")
+			}
+		}
+	})
+}
+
+// FuzzSanitizeYAMLEscapes ensures the escape sanitizer never panics and never
+// produces output shorter than its input (it can only expand \/ to \\/).
+func FuzzSanitizeYAMLEscapes(f *testing.F) {
+	seeds := [][]byte{
+		{},
+		[]byte("stage: build"),
+		[]byte(`if: "$CI_BRANCH =~ /^us\//"`),
+		[]byte(`"pattern: /^us\//"`),
+		[]byte(`'single quoted \/ unchanged'`),
+		[]byte(`"\n\t\r"`),
+		[]byte(`"nested \"quote\" inside"`),
+		[]byte(`'it''s fine'`),
+		[]byte(`"unclosed`),
+		{'"', '\\'},      // double-quoted string ending with a lone backslash
+		{'"', '\\', '/'}, // the exact sequence being rewritten
+	}
+	for _, s := range seeds {
+		f.Add(s)
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		out := sanitizeYAMLEscapes(data)
+		if len(out) < len(data) {
+			t.Fatalf("sanitizeYAMLEscapes shrank output: input len=%d output len=%d\ninput: %q",
+				len(data), len(out), data)
+		}
+	})
+}