feat(ui): show live scan progress and ETA for cache refresh

Broadcast typed scan_progress messages over /ws/fetch-progress from the
manual refresh/rebuild paths of ModelScanner and RecipeScanner, and
render percent, processed/total, current file name and an EMA-smoothed
ETA in the loading overlay. Hardcoded refresh strings move to i18n
(common.scanProgress); WS connection failure falls back to the previous
static loading behavior.

tests/services/test_recipe_scanner.py

@@ -9,6 +9,7 @@ import pytest
 
 from py.config import config
 from py.services import model_scanner as model_scanner_module
+from py.services import recipe_scanner as recipe_scanner_module
 from py.services.model_cache import ModelCache
 from py.services.model_hash_index import ModelHashIndex
 from py.services.model_scanner import CacheBuildResult, ModelScanner
@@ -4965,3 +4966,133 @@ async def test_find_all_duplicate_recipes_include_prompt_missing_gen_params(reci
     groups = await scanner.find_all_duplicate_recipes(include_prompt=True)
     # Recipes without gen_params/prompt normalize to empty prompt and match
     assert groups == {"abc:0.8\x1f": ["r1", "r2"]}
+
+
+class RecordingRecipeWebSocketManager:
+    """Minimal ws_manager stand-in that records broadcasts."""
+
+    def __init__(self) -> None:
+        self.payloads: list[Dict[str, Any]] = []
+        self.broadcasts: list[Dict[str, Any]] = []
+
+    async def broadcast_init_progress(self, payload: Dict[str, Any]) -> None:
+        self.payloads.append(payload)
+
+    async def broadcast(self, payload: Dict[str, Any]) -> None:
+        self.broadcasts.append(payload)
+
+
+def _write_progress_recipe_files(recipes_dir: Path, count: int) -> None:
+    recipes_dir.mkdir(parents=True, exist_ok=True)
+    for idx in range(count):
+        recipe_path = recipes_dir / f"progress-recipe-{idx}.recipe.json"
+        recipe_path.write_text(
+            json.dumps(
+                {
+                    "id": f"progress-recipe-{idx}",
+                    "file_path": str(recipes_dir / f"img-{idx}.png"),
+                    "title": f"Recipe {idx}",
+                    "modified": 0.0,
+                    "created_date": 0.0,
+                    "loras": [],
+                }
+            ),
+            encoding="utf-8",
+        )
+
+
+@pytest.mark.asyncio
+async def test_force_refresh_broadcasts_scan_progress(
+    tmp_path: Path, monkeypatch, recipe_scanner
+):
+    scanner, _stub = recipe_scanner
+    recipes_dir = Path(config.loras_roots[0]) / "recipes"
+    _write_progress_recipe_files(recipes_dir, 3)
+
+    ws_stub = RecordingRecipeWebSocketManager()
+    monkeypatch.setattr(recipe_scanner_module, "ws_manager", ws_stub)
+
+    await scanner.get_cached_data(force_refresh=True)
+    # Wait for the FTS index build so no background task outlives the loop.
+    if scanner._fts_index_task:
+        await scanner._fts_index_task
+
+    messages = ws_stub.broadcasts
+    assert messages, "expected scan_progress broadcasts"
+
+    started = messages[0]
+    assert started["type"] == "scan_progress"
+    assert started["status"] == "started"
+    assert started["stage"] == "scan_folders"
+    assert started["progress"] == 0
+    assert started["model_type"] == "recipe"
+    assert started["pageType"] == "recipes"
+    assert started["full_rebuild"] is True
+
+    count_messages = [m for m in messages if m["stage"] == "count_models"]
+    assert count_messages and count_messages[0]["total"] == 3
+
+    process_messages = [
+        m
+        for m in messages
+        if m["stage"] == "process_models" and m["status"] == "processing"
+    ]
+    assert process_messages, "expected at least one process_models update"
+    final_process = process_messages[-1]
+    assert final_process["processed"] == 3
+    assert final_process["total"] == 3
+    assert final_process["current_name"].endswith(".recipe.json")
+    for message in process_messages:
+        assert 0 < message["progress"] <= 99
+
+    completed = messages[-1]
+    assert completed["status"] == "completed"
+    assert completed["progress"] == 100
+    assert completed["elapsed_seconds"] >= 0
+    assert completed["total"] == 3
+
+
+def test_sync_init_without_report_progress_does_not_broadcast(
+    tmp_path: Path, monkeypatch, recipe_scanner
+):
+    """Startup path (initialize_in_background) must not emit scan_progress."""
+    scanner, _stub = recipe_scanner
+    recipes_dir = Path(config.loras_roots[0]) / "recipes"
+    _write_progress_recipe_files(recipes_dir, 2)
+
+    ws_stub = RecordingRecipeWebSocketManager()
+    monkeypatch.setattr(recipe_scanner_module, "ws_manager", ws_stub)
+
+    # Invalidate the persistent cache so the sync path performs a full
+    # directory scan, exactly like a force refresh but without progress
+    # reporting (this is how initialize_in_background invokes it).
+    scanner._persistent_cache.save_cache([], {})
+
+    scanner._initialize_recipe_cache_sync()
+
+    assert ws_stub.broadcasts == []
+
+
+def test_sync_init_reports_error_broadcast(
+    tmp_path: Path, monkeypatch, recipe_scanner
+):
+    scanner, _stub = recipe_scanner
+    recipes_dir = Path(config.loras_roots[0]) / "recipes"
+    _write_progress_recipe_files(recipes_dir, 1)
+
+    ws_stub = RecordingRecipeWebSocketManager()
+    monkeypatch.setattr(recipe_scanner_module, "ws_manager", ws_stub)
+
+    scanner._persistent_cache.save_cache([], {})
+
+    def raising_scan(self, recipes_dir, progress_loop=None):
+        raise RuntimeError("boom")
+
+    monkeypatch.setattr(RecipeScanner, "_full_directory_scan_sync", raising_scan)
+
+    scanner._initialize_recipe_cache_sync(report_progress=True)
+
+    messages = ws_stub.broadcasts
+    assert messages[0]["status"] == "started"
+    assert messages[-1]["status"] == "error"
+    assert messages[-1]["error"] == "boom"