docs: add project docs, GitHub DX, fire-tools stamp

- CLAUDE.md with commands, structure, key constraints
- .claude/rules/ coding standards + workflows
- docs/architecture.md with design decisions
- .github/ CI workflow, issue templates, PR template
- LICENSE (MIT)
- .fire-tools.json initialization stamp
- README.md rewritten with features, quick start, stack table

.github/workflows/ci.yml

@@ -0,0 +1,38 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  check:
+    name: Lint, type-check & 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: 20
+          cache: pnpm
+
+      - run: pnpm install --frozen-lockfile
+
+      - run: pnpm lint
+        name: Biome lint
+
+      - run: pnpm exec tsc --noEmit -p tsconfig.app.json
+        name: Type check
+
+      - run: pnpm test
+        name: Tests
+
+      - run: pnpm build
+        name: Production build