feat(civitai): sweep abandoned download partials at startup

Interrupted downloads leave url-hash .tmp resume files that nothing
cleans up; the queue that knows about them is in-memory only.

- iter_type_roots lists every folder downloads resolve into
- partials older than 7 days by mtime are deleted when the download
  manager starts; active partials always have a fresh mtime

modules/civitai/download_civitai.py

@@ -1,4 +1,5 @@
 import os
+import re
 import uuid
 import hashlib
 import threading
@@ -12,6 +13,10 @@ from modules import shared, paths
 from modules.logger import console
 
 
+STALE_PARTIAL_DAYS = 7
+TEMP_FILE_RE = re.compile(r'^[0-9a-f]{8}\.tmp$')
+
+
 @dataclass
 class DownloadItem:
     id: str = field(default_factory=lambda: uuid.uuid4().hex[:12])
@@ -57,6 +62,27 @@ class DownloadManager:
         self._lock = threading.Lock()
         self._max_workers = max_workers
         self._worker_count = 0
+        threading.Thread(target=self._sweep_stale_partials, daemon=True).start()
+
+    def _sweep_stale_partials(self):
+        # Partials double as resume state, but mtime stops moving the moment a
+        # download stops, so an untouched week-old .tmp is abandoned.
+        try:
+            from modules.civitai.filemanage_civitai import iter_type_roots
+            cutoff = time.time() - STALE_PARTIAL_DAYS * 86400
+            for root in iter_type_roots():
+                for path in root.rglob('*.tmp'):
+                    if not TEMP_FILE_RE.match(path.name):
+                        continue
+                    try:
+                        stat = path.stat()
+                        if stat.st_mtime < cutoff:
+                            path.unlink()
+                            log.info(f'CivitAI stale partial removed: file="{path}" size={stat.st_size/1024/1024:.0f}MB age>{STALE_PARTIAL_DAYS}d')
+                    except OSError as e:
+                        log.warning(f'CivitAI stale partial sweep: file="{path}" {e}')
+        except Exception as e:
+            log.warning(f'CivitAI stale partial sweep error: {e}')
 
     def enqueue(self, url: str, folder: str, filename: str, model_type: str = "",
                 expected_hash: str = "", token: str | None = None,

modules/civitai/filemanage_civitai.py

@@ -60,6 +60,25 @@ def get_type_folder(model_type: str, base_model: str = '') -> Path:
     return Path(paths.models_path) / fallback_dir
 
 
+def iter_type_roots() -> set[Path]:
+    """Every root folder downloads can resolve into, for maintenance sweeps."""
+    from modules import shared, paths
+    roots = set()
+    custom_json = getattr(shared.opts, 'civitai_save_type_folders', '') or ''
+    if custom_json.strip():
+        try:
+            import json
+            for folder in json.loads(custom_json).values():
+                p = Path(folder)
+                roots.add(p if p.is_absolute() else Path(paths.models_path) / folder)
+        except Exception:
+            pass
+    for opt_attr, fallback_dir in set(TYPE_MAP.values()) | {('unet_dir', 'UNET')}:
+        configured = (getattr(shared.opts, opt_attr, '') or '') if opt_attr else ''
+        roots.add(Path(configured) if configured else Path(paths.models_path) / fallback_dir)
+    return {r for r in roots if r.is_dir()}
+
+
 def resolve_save_path(model_type: str, model_name: str = "", base_model: str = "",
                       nsfw: bool = False, creator: str = "", model_id: int = 0,
                       version_id: int = 0, version_name: str = "") -> Path: