controller: Phase 7 dispatch — set_layout + cell_map (вместо streamselect)

Sync с n7.1-vf-cuda-grid-phase7 filter rework (один cuda_grid + native
runtime layout switching). Изменения:

  dispatch._set_layout:
    target: layout_filter_target (default cuda_grid@cg, был streamselect@layout)
    command: "set_layout <name>"  (был "map <index>")
    validation: PREDEFINED_LAYOUTS (был inst.layout_map)

  dispatch.set_main_cam:
    target: main_cam_filter_target (default cuda_grid@cg, был streamselect@main_cam)
    command: "cell_map <cell> <pad>" × max_cells
    cell 0 = main camera; cells 1..N-1 = identity rotation остальных pads
    (исключая main чтобы не дублировать в preview cells)

  dispatch.set_mpp_main:
    alias к set_main_cam — main_plus_preview тоже использует cell 0 как main.

  config.InstanceCfg:
    layout_filter_target / main_cam_filter_target / mpp_main_filter_target
    default = cuda_grid@cg (Phase 7 single filter)
    new max_cells: int = 4 (соответствует filter max_cells option)
    layout_map deprecated — оставлен для UI subset visibility (HTTP /layouts/{inst})

  http_api.set_layout:
    validation против PREDEFINED_LAYOUTS вместо layout_map

Frigate bridge не меняется — set_main_cam подпись та же (instance, cam_index).

Compile-test OK. Pipeline image: gx/cuda-grid-pipeline:phase7. Controller
image rebuild требуется для deploy.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

controller/cuda_grid_controller/http_api.py

@@ -82,10 +82,11 @@ def create_app(
 
     @app.post("/layout/{instance}/set")
     async def set_layout(instance: str, req: LayoutSetReq) -> dict[str, Any]:
-        inst = _check_instance(instance)
-        if req.layout not in inst.layout_map:
+        _check_instance(instance)
+        # Phase 7: validation против built-in PREDEFINED_LAYOUTS (filter ground truth).
+        if req.layout not in PREDEFINED_LAYOUTS:
             raise HTTPException(
-                400, f"unknown layout '{req.layout}'. Доступны: {list(inst.layout_map.keys())}"
+                400, f"unknown layout '{req.layout}'. Доступны: {PREDEFINED_LAYOUTS}"
             )
         await dispatcher.handle(instance, "layout.set", req.layout)
         return {"ok": True, "instance": instance, "layout": req.layout}
@@ -93,9 +94,12 @@ def create_app(
     @app.get("/layouts/{instance}")
     async def layouts_for_instance(instance: str) -> dict[str, Any]:
         inst = _check_instance(instance)
+        # UI shows только то что объявлено в config layout_map (subset). Если пуст —
+        # все доступные filter layouts.
+        ui_layouts = list(inst.layout_map.keys()) if inst.layout_map else PREDEFINED_LAYOUTS
         return {
             "instance": instance,
-            "layouts": list(inst.layout_map.keys()),
+            "layouts": ui_layouts,
             "current": await state.get_layout(instance),
         }