feat(recipes): remove deprecated Repair Metadata feature

The recipe "Repair Metadata" action has been marked Deprecated in the UI
for a while and cannot reliably recover recipes imported from CivitAI URLs
whose REST meta has no resources/hashes and whose image has no embedded
metadata (e.g. CivitAI-only generation data). Drop the feature end to end.

Backend:
- remove repair routes (repair, cancel-repair, recipe/{id}/repair,
  repair-bulk, repair-progress) and their handler mappings/methods
- remove RecipeScanner repair_all_recipes / repair_recipe_by_id /
  _repair_single_recipe and REPAIR_VERSION
- remove WebSocketManager recipe-repair progress channel
- drop repair_version column from the persistent recipe cache
- rematch mutual-exclusion now only checks rematch

Frontend:
- remove repair entries from per-recipe, bulk and global context menus
- remove repairRecipe / repairSelectedRecipes / repairRecipes + cancelRepair
  and the repairBulk API client method/endpoint
- drop recipe-repair i18n keys (synced across locales; doctor keys kept)

Tests/docs: delete test_recipe_repair.py, update scaffolding/routes/ws/
persistent-cache/integration tests and i18n guideline examples.

tests/routes/test_recipe_routes.py

@@ -1874,20 +1874,14 @@ async def test_create_from_example_does_not_recompute_stored_autov3(
 def _clean_recipe_run_progress_state():
     """Keep the shared WS manager run-state isolated between tests."""
     ws_manager._recipe_rematch_progress = None
-    ws_manager._recipe_repair_progress = None
     yield
     ws_manager._recipe_rematch_progress = None
-    ws_manager._recipe_repair_progress = None
 
 
 def _set_rematch_running(status: str = "processing") -> None:
     ws_manager._recipe_rematch_progress = {"status": status}
 
 
-def _set_repair_running(status: str = "processing") -> None:
-    ws_manager._recipe_repair_progress = {"status": status}
-
-
 async def test_rematch_recipes_starts_background_run(monkeypatch, tmp_path: Path) -> None:
     async with recipe_harness(monkeypatch, tmp_path) as harness:
         response = await harness.client.post("/api/lm/recipes/rematch")
@@ -1911,15 +1905,6 @@ async def test_rematch_recipes_409_when_rematch_running(monkeypatch, tmp_path: P
         assert "already in progress" in payload["error"].lower()
 
 
-async def test_rematch_recipes_409_when_repair_running(monkeypatch, tmp_path: Path) -> None:
-    async with recipe_harness(monkeypatch, tmp_path) as harness:
-        _set_repair_running()
-        response = await harness.client.post("/api/lm/recipes/rematch")
-        payload = await response.json()
-        assert response.status == 409
-        assert payload["success"] is False
-        assert "already in progress" in payload["error"].lower()
-
 
 async def test_rematch_recipe_409_when_rematch_running(monkeypatch, tmp_path: Path) -> None:
     async with recipe_harness(monkeypatch, tmp_path) as harness: