Add CI workflow for linting, type checking, and testing (#3)

* Add GitHub Actions CI workflow for lint, type-check, and tests

Adds .github/workflows/ci.yml with four jobs that run on every pull
request and push to main:

- lint: Biome lint & format check (pnpm lint)
- type-check: TypeScript strict type check (tsc --noEmit)
- test-unit: Vitest unit tests (pnpm test:unit)
- test-integration: Vitest integration tests (pnpm test:integration),
  conditional on DATABASE_URL secret being configured (requires a Neon
  PostgreSQL URL since the app uses @neondatabase/serverless)

Concurrent runs for the same ref are cancelled to avoid redundant CI usage.

https://claude.ai/code/session_0179RDnpCGY9iMg6yR5QBFFK

* Update GitHub Actions to latest major versions

- actions/checkout: v4 → v6 (latest: v6.0.2)
- actions/setup-node: v4 → v6 (latest: v6.2.0)
- pnpm/action-setup: already at latest (v4, v4.2.0)

https://claude.ai/code/session_0179RDnpCGY9iMg6yR5QBFFK

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: callicles

.github/workflows/ci.yml

@@ -0,0 +1,108 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Lint & Format
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: latest
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "20"
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Biome lint & format check
+        run: pnpm lint
+
+  type-check:
+    name: Type Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: latest
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "20"
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: TypeScript type check
+        run: npx tsc --noEmit
+
+  test-unit:
+    name: Unit Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: latest
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "20"
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run unit tests
+        run: pnpm test:unit
+
+  test-integration:
+    name: Integration Tests
+    runs-on: ubuntu-latest
+    # Requires a Neon-compatible DATABASE_URL secret.
+    # Add it under GitHub → Settings → Secrets and variables → Actions.
+    # The app uses @neondatabase/serverless (HTTP-based), so a standard local
+    # Postgres container is not sufficient — use a real Neon test database.
+    if: ${{ secrets.DATABASE_URL != '' }}
+    env:
+      DATABASE_URL: ${{ secrets.DATABASE_URL }}
+      # SESSION_SECRET can be any string for test purposes
+      SESSION_SECRET: ${{ secrets.SESSION_SECRET || 'ci-integration-test-secret' }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: latest
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "20"
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Apply database migrations
+        run: pnpm db:migrate
+
+      - name: Run integration tests
+        run: pnpm test:integration