chore: add GitHub Actions CI workflow

Runs lint, typecheck, test in parallel, then build on success.

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

Author: bluedbird

.github/workflows/ci.yml

@@ -0,0 +1,76 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - run: bun install --frozen-lockfile
+
+      - name: Biome check
+        run: bun run lint
+
+  typecheck:
+    name: Type Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - run: bun install --frozen-lockfile
+
+      - name: TypeScript
+        run: bun tsc --noEmit
+
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - run: bun install --frozen-lockfile
+
+      - name: Run tests
+        run: bun test
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    needs: [lint, typecheck, test]
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - run: bun install --frozen-lockfile
+
+      - name: Build server
+        run: bun build apps/server/src/index.ts --outdir dist/server --target bun
+
+      - name: Build CLI
+        run: bun build apps/cli/src/index.ts --outdir dist/cli --target bun