refactor(1): use general fast_asset_file_check helper for fast check

app/database/helpers/fast_check.py

@@ -0,0 +1,19 @@
+import os
+from typing import Optional
+
+
+def fast_asset_file_check(
+    *,
+    mtime_db: Optional[int],
+    size_db: Optional[int],
+    stat_result: os.stat_result,
+) -> bool:
+    if mtime_db is None:
+        return False
+    actual_mtime_ns = getattr(stat_result, "st_mtime_ns", int(stat_result.st_mtime * 1_000_000_000))
+    if int(mtime_db) != int(actual_mtime_ns):
+        return False
+    sz = int(size_db or 0)
+    if sz > 0:
+        return int(stat_result.st_size) == sz
+    return True