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

backend/scripts/hash_password.py

@@ -0,0 +1,12 @@
+"""Generate a bcrypt password hash for config.yml."""
+import sys
+from passlib.context import CryptContext
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+if len(sys.argv) < 2:
+    print("Usage: python scripts/hash_password.py <password>")
+    sys.exit(1)
+
+password = sys.argv[1]
+print(pwd_context.hash(password))