v0.11.0 -> v0.12.0: startup hardware self-assessment (Roadmap J)

- hardware.py: assess_hardware() probes RAM, CPU, GPU VRAM (rocm-smi),
  llama-server, Qdrant, SearXNG reachability — writes hardware_state.json
- routers/hardware.py: GET /api/hardware (no auth) returns snapshot
- app.py: calls assess_hardware() in lifespan after init_db()
- 4 new tests: all services reachable, rocm-smi absent, llama unreachable,
  HTTP endpoint

routers/hardware.py

@@ -0,0 +1,15 @@
+"""JarvisChat routers — Hardware self-assessment endpoint."""
+import json
+
+from fastapi import APIRouter
+
+import hardware
+
+router = APIRouter()
+
+
+@router.get("/api/hardware")
+async def get_hardware_state():
+    if hardware.HARDWARE_STATE_PATH.exists():
+        return json.loads(hardware.HARDWARE_STATE_PATH.read_text())
+    return {"status": "not_ready", "message": "Hardware assessment not yet complete"}