chore(ci): add commitlint workflow + config

Adds a CI workflow that lints commit messages on every PR using
wagoid/commitlint-github-action with @commitlint/config-conventional
rules. Workflow-only approach (no devDependency or husky hook
changes — zero impact on local dev environment).

Allowed types: feat, fix, docs, style, refactor, perf, test, chore,
build, ci, revert. Header max length 100 chars (warning only).

Plan: .claude-plans/help-me-enable-all-zany-gosling.md (Track C).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: JCBauza

.commitlintrc.json

@@ -0,0 +1,13 @@
+{
+  "extends": ["@commitlint/config-conventional"],
+  "rules": {
+    "type-enum": [
+      2,
+      "always",
+      ["feat", "fix", "docs", "style", "refactor", "perf", "test", "chore", "build", "ci", "revert"]
+    ],
+    "subject-case": [0, "always"],
+    "header-max-length": [1, "always", 100]
+  }
+}
+

.github/workflows/commitlint.yml

@@ -0,0 +1,20 @@
+name: Commit Lint
+on:
+  pull_request:
+    branches: [main, master]
+permissions:
+  contents: read
+jobs:
+  commitlint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Lint commits in PR
+        uses: wagoid/commitlint-github-action@v6
+        with:
+          configFile: ".commitlintrc.json"
+          failOnWarnings: false
+          firstParent: false
+