ci: run typecheck + build + tests on every PR (#66)

Adds a GitHub Actions workflow that runs npm run typecheck, npx
electron-vite build, and npx vitest run on every PR (and on pushes to
main as a safety net). Previously these only ran locally, so PRs could
land with broken types or tests if the author skipped the pre-commit
ritual.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: frenchie4111

.github/workflows/ci.yml

@@ -0,0 +1,42 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+# Cancel an in-flight CI run when a new commit lands on the same branch.
+# Saves CI minutes during rapid pushes; the latest commit is what matters.
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      # --legacy-peer-deps because electron-vite@5 declares a peer range
+      # that npm's strict resolver rejects against the installed vite@7.
+      # Matches the developer-facing install instructions.
+      - name: Install dependencies
+        run: npm install --legacy-peer-deps
+
+      # electron-vite build does NOT run tsc on its own — so typecheck
+      # is a separate, required gate.
+      - name: Typecheck
+        run: npm run typecheck
+
+      # Catches missing imports, asset resolution errors, and other
+      # bundler-level issues that tsc alone misses.
+      - name: Build
+        run: npx electron-vite build
+
+      - name: Tests
+        run: npx vitest run

CLAUDE.md

@@ -467,6 +467,9 @@ These are how the user wants Claude to behave when working on this repo:
    - `npx electron-vite build` — catches missing imports, asset resolution,
      and other bundler-level issues.
    Run `npx vitest run` too if the change could affect reducer/FSM behavior.
+   PR-time CI (`.github/workflows/ci.yml`) runs all three on every PR as a
+   safety net, but the local pre-commit ritual still catches issues before
+   you push.
 
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