chore: enforce dev base branch and gitignore build artifacts (#2108)

* chore: enforce dev base branch and gitignore build artifacts

Two recurring contributor mistakes are now blocked at the tooling layer:

1. PRs targeting main instead of dev — the new `base-branch-check` job in
   pr-check.yml fails CI immediately with a one-line fix command.

2. dist/ and bridge/ build artifacts in PRs — added to .gitignore so they
   no longer appear as uncommitted changes after `npm run build`.

.github/CLAUDE.md also documents both rules so AI-assisted contributors
pick them up at session start, before they can make the mistake.

Directive: dist/ and bridge/ are generated by `npm run build` — never commit them.
Directive: all PRs must target `dev`; `main` is merged into by release workflow only.

* fix(ci): rerun base-branch-check on PR base edits

Add `edited` to the pull_request event types so the base-branch-check
job fires when a contributor changes their PR base via gh pr edit --base dev,
preventing stale failed statuses after the fix is applied.

Confidence: high
Scope-risk: narrow

.github/CLAUDE.md

@@ -108,6 +108,12 @@ Kill switches: `DISABLE_OMC`, `OMC_SKIP_HOOKS` (comma-separated).
 State: `.omc/state/`, `.omc/state/sessions/{sessionId}/`, `.omc/notepad.md`, `.omc/project-memory.json`, `.omc/plans/`, `.omc/research/`, `.omc/logs/`
 </worktree_paths>
 
+<contribution_rules>
+**PRs must always target `dev`, never `main`.** `main` is release-only and is only ever merged into by the maintainer via the release workflow. If you open a PR and realize it targets `main`, use `gh pr edit --base dev` to fix it before asking for review.
+
+**Never commit `dist/` or `bridge/`.** These are build artifacts generated by `npm run build`. They are gitignored. If they appear in your diff, run `git restore dist/ bridge/` before committing. Committing them inflates PR size, creates merge conflicts, and obscures the actual changes under review.
+</contribution_rules>
+
 ## Setup
 
 Say "setup omc" or run `/oh-my-claudecode:omc-setup`.

.github/workflows/pr-check.yml

@@ -2,7 +2,7 @@ name: PR Check
 
 on:
   pull_request:
-    types: [opened, synchronize, reopened]
+    types: [opened, synchronize, reopened, edited]
   workflow_dispatch:
 
 permissions:
@@ -63,6 +63,22 @@ jobs:
 
             console.log(`PR Stats: +${additions} -${deletions} (${changedFiles} files) → ${sizeLabel}`);
 
+  base-branch-check:
+    name: Base Branch Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Require dev base branch
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const base = context.payload.pull_request.base.ref;
+            if (base !== 'dev') {
+              core.setFailed(
+                `PRs must target the \`dev\` branch, not \`${base}\`. ` +
+                `Fix with: gh pr edit ${context.issue.number} --base dev`
+              );
+            }
+
   draft-check:
     name: Draft PR Check
     runs-on: ubuntu-latest

.gitignore

@@ -24,3 +24,7 @@ benchmarks/harsh-critic/scoring/*.d.ts.map
 
 # Release body is generated dynamically — never commit stale copies
 .github/release-body.md
+
+# Build artifacts — generated by `npm run build`, never commit
+dist/
+bridge/