Fix calendar bugs, unblock build, add tests + CI, harden reliability

.github/workflows/ci.yml

@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      # Blocking gates — these must pass before the app can be deployed.
+      - name: Test
+        run: npm test
+
+      - name: Build
+        run: npm run build
+
+      # Informational for now (the codebase still has pre-existing `any`s to
+      # clean up); flip to blocking once the lint backlog is cleared.
+      - name: Lint
+        run: npm run lint
+        continue-on-error: true

.gitignore

@@ -39,3 +39,9 @@ yarn-error.log*
 # typescript
 *.tsbuildinfo
 next-env.d.ts
+
+# --- LinearCal deploy agent: credentials + local tooling, NEVER commit ---
+# (the .env* rule above misses files that *end* in .env, like linearcal-agent.env)
+*.env
+linearcal-agent.env
+/deploy-agent/