feat(cli): .glint.yml config and inline suppression comments

Adds project-level configuration and per-job suppression directives:

.glint.yml (searched from pipeline dir up to the git root):
- ignore: [GL007, GL032] — suppress rules globally for the project
- severity: {GL004: warning} — override rule severity (error/warning/ignore)
- stages: [quality] — extra stages beyond the pipeline's stages: block
- token: / url: / cache_dir: — defaults for flags; lower priority than
  CLI flags and environment variables

Inline suppression (# glint: ignore):
- Place "# glint: ignore GL007" immediately before a job definition to
  suppress that rule for the specific job only
- Multiple rules: "# glint: ignore GL007, GL032" (comma or space separated)
- Wildcard: "# glint: ignore all" suppresses every finding for the job
- Suppressions are scoped to the annotated job; pipeline-level findings
  are unaffected
- Parsed from yaml.Node head/line comments in the first parse pass;
  stored in Pipeline.Suppressions (root file only, not includes)

New packages: internal/config (Load, walk-up search, .git boundary stop)
New files: cmd/glint/filter.go (applyConfig, isSuppressed helpers)
Tests: config_test.go, parser_suppress_test.go, filter_test.go
Validate fixtures: testdata/config_ignored/, config_severity/, config_suppress/

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

CHANGELOG.md

@@ -5,6 +5,20 @@ 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).
 
+## [0.2.19] - 2026-06-14
+
+### Added
+
+- **`.glint.yml` project config file** — glint now searches for a `.glint.yml` file starting from the pipeline file's directory and walking up to the first `.git` boundary. Supported keys:
+  - `ignore: [GL007, GL032]` — suppress rules globally for the project.
+  - `severity: {GL004: warning}` — override rule severity (`error`, `warning`, or `ignore`). `ignore` is equivalent to listing the rule in `ignore:`.
+  - `stages: [quality]` — declare extra stage names that are valid beyond those in the pipeline's own `stages:` block; jobs in these stages are not flagged by GL004.
+  - `token: glpat-xxx` — default GitLab personal access token (lower priority than the `--token` flag and `GITLAB_TOKEN` env var).
+  - `url: https://gitlab.example.com` — default GitLab instance URL.
+  - `cache_dir: ~/.cache/glint` — default cache directory for fetched remote includes.
+
+- **Inline suppression comments** — a `# glint: ignore RULE` comment placed immediately before a job definition suppresses that rule for the specific job. Multiple rules can be comma- or space-separated (`# glint: ignore GL007, GL032`). Use `# glint: ignore all` to suppress every finding for the job. Suppressions are scoped to the annotated job; pipeline-level findings are unaffected.
+
 ## [0.2.18] - 2026-06-14
 
 ### Added