chore(ci): migrate workflows to Bun and remove unused lock/config files

- Replace npm with Bun in CI and release workflows
- Remove package-lock.json (Bun uses bun.lock)
- Remove .coderabbit.yaml and add to .gitignore
- Keep setup-node only for npm publish step in release workflow

Author: ZeR020

.coderabbit.yaml

@@ -15,22 +15,21 @@ jobs:
     steps:
       - uses: actions/checkout@v5
 
-      - name: Setup Node.js
-        uses: actions/setup-node@v5
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
         with:
-          node-version: '24'
-          cache: 'npm'
+          bun-version: latest
 
-      - run: npm ci
+      - run: bun install
 
       - name: Typecheck
-        run: npm run typecheck
+        run: bun run typecheck
 
       - name: Build
-        run: npm run build
+        run: bun run build
 
       - name: Test
-        run: npm test
+        run: bun test
 
       - name: Audit
-        run: npm audit --audit-level=moderate
+        run: bun audit

.github/workflows/ci.yml

@@ -15,21 +15,19 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Setup Node.js for npm publish
-        uses: actions/setup-node@v5
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
         with:
-          node-version: '24'
-          registry-url: 'https://registry.npmjs.org'
-          cache: 'npm'
+          bun-version: latest
 
-      - run: npm ci
+      - run: bun install
 
-      - run: npm run typecheck
+      - run: bun run typecheck
 
-      - run: npm run build
+      - run: bun run build
 
       - name: Run tests
-        run: npm test
+        run: bun test
 
       - name: Check release state
         id: release_state
@@ -54,6 +52,13 @@ jobs:
             echo "github_release_exists=false" >> "$GITHUB_OUTPUT"
           fi
 
+      - name: Setup Node.js for npm publish
+        if: steps.release_state.outputs.npm_published == 'false'
+        uses: actions/setup-node@v5
+        with:
+          node-version: '24'
+          registry-url: 'https://registry.npmjs.org'
+
       - name: Publish to npm
         if: steps.release_state.outputs.npm_published == 'false'
         run: npm publish --access public

.github/workflows/release.yml

@@ -1,5 +1,6 @@
 # dependencies (bun install)
 node_modules
+package-lock.json
 
 # output
 out
@@ -37,6 +38,9 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 docs/plans/
 .sisyphus
 
+# CodeRabbit configuration (optional AI code review tool)
+.coderabbit.yaml
+
 # test artifacts & temporary databases
 *.test.db
 *.tmp.db