ci: add GitHub Actions workflow for tests and benchmarks

- test job: pnpm install, type check (tsc), unit tests (vitest)
- bench job: generate data, start wrangler dev, seed R2, run benchmarks
- Runs on push to main and PRs

Author: teamchong

.github/workflows/ci.yml

@@ -0,0 +1,68 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: 9
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - run: pnpm install --frozen-lockfile
+
+      - name: Type check
+        run: pnpm build
+
+      - name: Unit tests
+        run: pnpm test
+
+  bench:
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: 9
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - run: pnpm install --frozen-lockfile
+
+      - name: Generate benchmark data
+        run: npx tsx scripts/generate-bench-data.ts
+
+      - name: Start wrangler dev
+        run: |
+          pnpm dev &
+          # Wait for worker to be ready
+          for i in $(seq 1 30); do
+            if curl -sf http://localhost:8787/health > /dev/null 2>&1; then
+              echo "Worker ready"
+              break
+            fi
+            sleep 1
+          done
+
+      - name: Seed local R2
+        run: npx tsx scripts/seed-local-r2.ts
+
+      - name: Run benchmarks
+        run: npx tsx scripts/bench.ts