init: initial commit

- ticker / QR ad overlay / break slide graphics (1920×1080) with all
  geometry derived from one shared module (src/shared/obs-geometry.mjs)
- OBS scene-collection generator (scripts/generate-obs-scenes.mjs) and a
  read-only in-dashboard setup verifier, both driven by the same module
- en/sr dashboard i18n selected via bundle config; configschema.json with
  neutral first-run defaults seeded from optional branding config
- install.sh / systemd user service / update.sh for venue deployment
- reference OBS scene collection + profile from a real venue as fixtures

.github/workflows/build.yml

@@ -0,0 +1,23 @@
+name: build
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+      - run: npm ci
+      - run: npm run build
+      - run: npx tsc --noEmit -p src/dashboard/tsconfig.json
+      - run: npx tsc --noEmit -p src/graphics/tsconfig.json
+      - run: npx tsc --noEmit -p src/extension/tsconfig.json
+      - run: node scripts/generate-obs-scenes.mjs --out /tmp/smoke.json
+      - run: node -e "JSON.parse(require('fs').readFileSync('/tmp/smoke.json'))"