feat: Phase 1 scaffold — frontend canvas + backend skeleton

Frontend:
- Vite + React 18 + TypeScript + Tailwind v4 + Shadcn/ui
- React Flow v12 canvas with all 11 node types and 5 edge types
- Dark theme with project design system (cyan, green, orange, purple accents)
- Collapsible sidebar, toolbar, detail panel
- Zustand store for canvas state
- Demo data with 10 nodes and 10 edges

Backend:
- FastAPI + SQLAlchemy async + SQLite (Python 3.13)
- DB models: Node, Edge, CanvasState, PendingDevice, ScanRun
- REST API routes: auth, nodes, edges, canvas, scan, status (WebSocket)
- JWT auth + bcrypt via config.yml
- Pydantic v2 schemas

Infra:
- GitHub Actions quality + security workflows
- .gitignore, .env.example, verify-tooling.sh, security-check.sh

.github/workflows/quality.yml

@@ -0,0 +1,40 @@
+name: Quality
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  frontend:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: frontend
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+          cache-dependency-path: frontend/package-lock.json
+      - run: npm ci
+      - run: npm run lint
+      - run: npm run typecheck
+      - run: npm test -- --run
+
+  backend:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: backend
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+      - run: pip install -r requirements.txt
+      - run: ruff check .
+      - run: mypy app/
+      - run: pytest

.github/workflows/security.yml

@@ -0,0 +1,36 @@
+name: Security
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  schedule:
+    - cron: '0 9 * * 1'  # Weekly on Monday
+
+jobs:
+  secrets-scan:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Detect secrets
+        uses: trufflesecurity/trufflehog@main
+        with:
+          path: ./
+
+  dependency-audit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+      - name: NPM Audit
+        run: cd frontend && npm audit --audit-level=high
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+      - name: Safety check
+        run: pip install safety && safety check -r backend/requirements.txt