feat(cli)!: subcommand CLI, graph tree mode, local include resolution

BREAKING CHANGES:
- `glint <file>` removed; use `glint check <file>`
- `--graph <mode>` removed; use `glint graph [mode]`
- `--graph-out` renamed to `--out` on `glint graph`

feat(cli): ruff-style subcommands — `glint check` and `glint graph [mode]`
feat(graph): `glint graph tree` — terminal job tree with context annotations
feat(graph): context flags (--branch/--tag/--source/--var) on `glint graph`
feat(resolver): recursive local include resolution from disk
fix(resolver): extends unknown base emits warning instead of fatal error
fix(model): script/before_script/after_script accept block scalar string form
test(linter): Samba project CI fixtures as integration tests
chore(build): fix .gitignore to not exclude cmd/glint/ directory
docs: update CHANGELOG, README, ROADMAP for v0.2.0

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

internal/linter/samba_test.go

@@ -0,0 +1,89 @@
+package linter_test
+
+import (
+	"path/filepath"
+	"testing"
+
+	"git.k3nny.fr/glint/internal/fetcher"
+	"git.k3nny.fr/glint/internal/linter"
+	"git.k3nny.fr/glint/internal/model"
+	"git.k3nny.fr/glint/internal/resolver"
+)
+
+// TestSambaCI verifies that the Samba project's .gitlab-ci.yml (a real-world
+// pipeline that is valid on GitLab) produces no Error findings.
+// These files exercise local include resolution and multi-level extends chains.
+func TestSambaCI(t *testing.T) {
+	entryPoint := "../../samba-testdata/.gitlab-ci.yml"
+
+	p, err := model.Parse(entryPoint)
+	if err != nil {
+		t.Fatalf("Parse: %v", err)
+	}
+
+	rootDir := filepath.Dir(filepath.Clean(entryPoint))
+	incWarnings, _ := resolver.ResolveIncludes(p, fetcher.GitLabConfig{}, rootDir)
+	for _, w := range incWarnings {
+		t.Logf("include warning: %s", w)
+	}
+
+	extWarnings, err := resolver.Resolve(p)
+	if err != nil {
+		t.Fatalf("Resolve: %v", err)
+	}
+	for _, w := range extWarnings {
+		t.Logf("extends warning: job %q extends unknown %q", w.Job, w.Base)
+	}
+
+	findings := linter.Lint(p)
+
+	for _, f := range findings {
+		if f.Severity == linter.Error {
+			t.Errorf("unexpected error finding on valid Samba CI: %s", f)
+		}
+	}
+}
+
+// TestSambaCIEntryFiles verifies all of the Samba entry-point files
+// (files that can each act as the top-level CI file) lint without errors.
+func TestSambaCIEntryFiles(t *testing.T) {
+	entryPoints := []struct {
+		name string
+		path string
+	}{
+		{"default", "../../samba-testdata/.gitlab-ci.yml"},
+		{"coverage", "../../samba-testdata/.gitlab-ci-coverage.yml"},
+		{"private", "../../samba-testdata/.gitlab-ci-private.yml"},
+	}
+
+	for _, tc := range entryPoints {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			p, err := model.Parse(tc.path)
+			if err != nil {
+				t.Fatalf("Parse: %v", err)
+			}
+
+			rootDir := filepath.Dir(filepath.Clean(tc.path))
+			incWarnings, _ := resolver.ResolveIncludes(p, fetcher.GitLabConfig{}, rootDir)
+			for _, w := range incWarnings {
+				t.Logf("include warning: %s", w)
+			}
+
+			extWarnings, err := resolver.Resolve(p)
+			if err != nil {
+				t.Fatalf("Resolve: %v", err)
+			}
+			for _, w := range extWarnings {
+				t.Logf("extends warning: job %q extends unknown %q", w.Job, w.Base)
+			}
+
+			findings := linter.Lint(p)
+			for _, f := range findings {
+				if f.Severity == linter.Error {
+					t.Errorf("unexpected error finding: %s", f)
+				}
+			}
+		})
+	}
+}