Phase 2: Volume Wizard, GPU & device passthrough (0.2.0)

Backend:
- gpu_service: detect NVIDIA (nvidia-smi) + AMD/Intel (/dev/dri, sysfs);
  inject helpers (nvidia deploy.reservations, /dev/dri + groups + LIBVA)
- volume_service: list/orphaned/prune volumes; NFS/SMB/named/bind/tmpfs
  YAML generation (generate-yaml)
- device_service: USB/TTY/DRI detection + sandboxed host path browser
- compose_edit_service: server-side merge of volume/gpu/device fragments
- routers: volumes (+host paths), editor (services/add-volume/set-gpu/
  add-device/remove-device/set-privileged), system gpus+devices
- compose: bind-mount /dev:ro for detection

Frontend:
- split-pane StackEditor with helper panel (service picker + tabs)
- VolumeWizard (bind/named/nfs/smb/tmpfs) + HostPathBrowser
- GPUSelector, DevicePanel; api clients for volumes/editor/system

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/routers/editor.py

@@ -0,0 +1,76 @@
+"""Editor helper endpoints — merge wizard fragments into compose YAML."""
+from __future__ import annotations
+
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel
+
+from auth import get_current_user
+from models.user import User
+from services import compose_edit_service as edit
+
+router = APIRouter(prefix="/api/editor", tags=["editor"])
+
+
+class AddVolumeBody(BaseModel):
+    yaml: str
+    service: str
+    spec: dict
+
+
+class SetGpuBody(BaseModel):
+    yaml: str
+    service: str
+    config: dict
+
+
+class DeviceBody(BaseModel):
+    yaml: str
+    service: str
+    host_path: str
+    target: str | None = None
+
+
+class PrivilegedBody(BaseModel):
+    yaml: str
+    service: str
+    value: bool
+
+
+def _run(fn, *args) -> dict:
+    try:
+        return {"yaml": fn(*args)}
+    except edit.EditError as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc
+
+
+@router.post("/services")
+def services(body: dict, _user: User = Depends(get_current_user)) -> dict:
+    try:
+        return {"services": edit.list_services(body.get("yaml", ""))}
+    except edit.EditError as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc
+
+
+@router.post("/add-volume")
+def add_volume(body: AddVolumeBody, _user: User = Depends(get_current_user)) -> dict:
+    return _run(edit.add_volume, body.yaml, body.service, body.spec)
+
+
+@router.post("/set-gpu")
+def set_gpu(body: SetGpuBody, _user: User = Depends(get_current_user)) -> dict:
+    return _run(edit.set_gpu, body.yaml, body.service, body.config)
+
+
+@router.post("/add-device")
+def add_device(body: DeviceBody, _user: User = Depends(get_current_user)) -> dict:
+    return _run(edit.add_device, body.yaml, body.service, body.host_path, body.target)
+
+
+@router.post("/remove-device")
+def remove_device(body: DeviceBody, _user: User = Depends(get_current_user)) -> dict:
+    return _run(edit.remove_device, body.yaml, body.service, body.host_path)
+
+
+@router.post("/set-privileged")
+def set_privileged(body: PrivilegedBody, _user: User = Depends(get_current_user)) -> dict:
+    return _run(edit.set_privileged, body.yaml, body.service, body.value)