Phase 18: image prune (dangling/unused), local + agent (0.24.0)

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

backend/routers/images.py

@@ -1,15 +1,21 @@
 """Image listing + update-check endpoints."""
 from __future__ import annotations
 
-from fastapi import APIRouter, Depends
+from fastapi import APIRouter, Depends, Query, Request
+from sqlmodel import Session
 
 from auth import get_current_user, require_admin
+from database import get_session
 from models.user import User
-from services import image_service, update_service
+from services import audit_service, image_service, update_service
 
 router = APIRouter(prefix="/api/images", tags=["images"])
 
 
+def _ip(request: Request) -> str:
+    return request.client.host if request.client else "unknown"
+
+
 @router.get("")
 def list_images(_user: User = Depends(get_current_user)) -> list[dict]:
     return image_service.list_images()
@@ -23,3 +29,19 @@ def updates(_user: User = Depends(get_current_user)) -> dict:
 @router.post("/check")
 async def check(_user: User = Depends(require_admin)) -> dict:
     return await update_service.check_all()
+
+
+@router.post("/prune")
+def prune(
+    request: Request,
+    all_unused: bool = Query(False, alias="all"),
+    session: Session = Depends(get_session),
+    user: User = Depends(require_admin),
+) -> dict:
+    result = image_service.prune_images(all_unused)
+    audit_service.record(
+        session, user=user.username, action="image.prune", target="*",
+        detail=f"all={all_unused} reclaimed={result.get('SpaceReclaimed')}",
+        ip=_ip(request),
+    )
+    return result