ci: add lint and typecheck workflow on push/PR

.github/workflows/ci.yml

@@ -0,0 +1,36 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  quality:
+    name: Lint & Typecheck
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Lint
+        run: bun run lint
+
+      # Type checking is disabled until pre-existing TS errors on main
+      # are resolved (missing exports from layout redesign #207, missing
+      # @types/node, etc.). Uncomment once the codebase passes tsc:
+      #
+      # - name: Build workspace packages
+      #   run: bun run build
+      #
+      # - name: Type check
+      #   run: bun run check-types