Perf: serve stacks list from one Docker call; registry host → 10.10.6.10 (0.21.6)

Stacks overview and detail were doing an N+1 inspect storm: list_stacks
called containers_for_stack AND compute_status (which re-fetched) per
stack, and containers.list(sparse=False) full-inspects every container
plus c.image triggered an image-inspect each. For N stacks that was
~2N*(1 list + M inspects + M image-inspects) sequential socket round
trips (~1s for just 2 stacks, growing linearly).

- compose_service.stack_status_summaries(): one low-level
  api.containers(all=True) summary call grouped by compose project label
  → whole list served in a single Docker round-trip (~10x faster).
- compute_status() takes optional pre-fetched containers; get_stack and
  _stack_summary no longer double-fetch.
- containers_for_stack() reads the image name from the inspect it already
  has instead of c.image (drops the per-container image-inspect).
- Same batching applied to the agent's stack list/detail.

Also: Forgejo (registry + git) moved to 10.10.6.10:3020 — updated image
refs in docker-compose.yml, agent/Dockerfile, agent/docker-compose.yml.

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

backend/agent_app.py

@@ -62,7 +62,7 @@ def _map_docker(exc: DockerError):
         raise HTTPException(status_code=code, detail=exc.detail or exc.error)
     raise exc  # falls through to the global 502 DockerError handler
 
-AGENT_VERSION = "0.21.5"
+AGENT_VERSION = "0.21.6"
 
 
 # --------------------------------------------------------------------------- #
@@ -137,20 +137,31 @@ def _file_guard(fn, *args, **kwargs):
 # --------------------------------------------------------------------------- #
 
 
-def _summary(stack_id: str) -> dict:
-    try:
-        containers = compose_service.containers_for_stack(stack_id)
-        status = compose_service.compute_status(stack_id)
-    except DockerError:
-        containers = []
-        status = "unknown"
+def _summary(stack_id: str, summaries: dict | None = None) -> dict:
+    if summaries is None:
+        try:
+            containers = compose_service.containers_for_stack(stack_id)
+            total = len(containers)
+            running = sum(1 for c in containers if c.state == "running")
+            status = compose_service.compute_status(stack_id, containers)
+        except DockerError:
+            total = running = 0
+            status = "unknown"
+    else:
+        info = summaries.get(stack_id)
+        total = info["total"] if info else 0
+        running = info["running"] if info else 0
+        if compose_service.is_busy(stack_id):
+            status = "updating"
+        else:
+            status = info["status"] if info else "stopped"
     return {
         "id": stack_id,
         "name": stack_id,
         "description": None,
         "status": status,
-        "service_count": len(containers),
-        "running_count": sum(1 for c in containers if c.state == "running"),
+        "service_count": total,
+        "running_count": running,
         "created_at": None,
         "updated_at": None,
     }
@@ -245,7 +256,11 @@ def system() -> dict:
 
 @app.get("/agent/stacks", dependencies=[Depends(verify_token)])
 def list_stacks() -> list[dict]:
-    return [_summary(sid) for sid in compose_service.discover_stacks()]
+    try:
+        summaries = compose_service.stack_status_summaries()
+    except DockerError:
+        summaries = {}
+    return [_summary(sid, summaries) for sid in compose_service.discover_stacks()]
 
 
 @app.get("/agent/stacks/stats", dependencies=[Depends(verify_token)])
@@ -259,8 +274,9 @@ def get_stack(stack_id: str) -> dict:
     if not os.path.isdir(directory):
         raise HTTPException(status_code=404, detail=f"Stack '{stack_id}' not found")
     try:
-        containers = [asdict(c) for c in compose_service.containers_for_stack(stack_id)]
-        status = compose_service.compute_status(stack_id)
+        raw = compose_service.containers_for_stack(stack_id)
+        containers = [asdict(c) for c in raw]
+        status = compose_service.compute_status(stack_id, raw)
     except DockerError:
         containers = []
         status = "unknown"