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.

static/js/api/recipeApi.js

@@ -20,7 +20,6 @@ const RECIPE_ENDPOINTS = {
     move: '/api/lm/recipe/move',
     moveBulk: '/api/lm/recipes/move-bulk',
     bulkDelete: '/api/lm/recipes/bulk-delete',
-    repairBulk: '/api/lm/recipes/repair-bulk',
     rematchBulk: '/api/lm/recipes/rematch-bulk',
     rematchSingle: '/api/lm/recipe/{recipe_id}/rematch',
 };
@@ -678,38 +677,6 @@ export class RecipeSidebarApiClient {
         };
     }
 
-    async repairBulkModels(filePaths) {
-        if (!filePaths || filePaths.length === 0) {
-            throw new Error('No file paths provided');
-        }
-
-        const recipeIds = filePaths
-            .map((path) => extractRecipeId(path))
-            .filter((id) => !!id);
-
-        if (recipeIds.length === 0) {
-            throw new Error('No recipe IDs could be derived from file paths');
-        }
-
-        const response = await fetch(this.apiConfig.endpoints.repairBulk, {
-            method: 'POST',
-            headers: {
-                'Content-Type': 'application/json',
-            },
-            body: JSON.stringify({
-                recipe_ids: recipeIds,
-            }),
-        });
-
-        const result = await response.json();
-
-        if (!response.ok || !result.success) {
-            throw new Error(result.error || 'Failed to repair recipes');
-        }
-
-        return result;
-    }
-
     async rematchBulkModels(filePaths) {
         if (!filePaths || filePaths.length === 0) {
             throw new Error('No file paths provided');