docs: move dev quick-reference to Instructions.md

Docs/Instructions.md

@@ -226,3 +226,34 @@ Verify against [Architekture.md](Architekture.md) and the project structure rule
 - **Never** push directly to `main` — always use feature branches.
 - **Never** skip the review step — sloppy code compounds over time.
 - **Never** leave a task half-done — finish it or revert it.
+
+---
+
+## 7. Dev Quick-Reference
+
+### Start / stop the stack
+
+```bash
+make up      # start all containers (from repo root)
+make down    # stop all containers
+make logs    # tail logs
+```
+
+Backend: `http://127.0.0.1:8000` · Frontend (Vite proxy): `http://127.0.0.1:5173`
+
+### API login (dev)
+
+The frontend SHA256-hashes the password before sending it to the API.  
+The session cookie is named `bangui_session`.
+
+```bash
+# Dev master password: Hallo123!
+HASHED=$(echo -n "Hallo123!" | sha256sum | awk '{print $1}')
+TOKEN=$(curl -s -X POST http://127.0.0.1:8000/api/auth/login \
+  -H 'Content-Type: application/json' \
+  -d "{\"password\":\"$HASHED\"}" \
+  | python3 -c 'import sys,json; print(json.load(sys.stdin)["token"])')
+
+# Use token in subsequent requests:
+curl -H "Cookie: bangui_session=$TOKEN" http://127.0.0.1:8000/api/dashboard/status
+```