style: apply ruff format across backend + scripts (line-length 100)

Mechanical, whole-tree `ruff format` pass — no behaviour change. Recorded in
.git-blame-ignore-revs (next commit) so git blame skips it.

backend/alembic/versions/0060_plex_jsonb_null_normalize.py

@@ -9,6 +9,7 @@ This one-time data fixup rewrites those scalars to SQL NULL so the columns are u
 forward-only: a SQL NULL is indistinguishable from the old JSON `null` to every reader (the guards
 treat both as "not an array"), so there is nothing meaningful to downgrade. No schema change.
 """
+
 from typing import Sequence, Union
 
 from alembic import op
@@ -25,9 +26,7 @@ _COLS = ("genres", "directors", "cast_names", "collection_keys")
 def upgrade() -> None:
     for table in _TABLES:
         for col in _COLS:
-            op.execute(
-                f"UPDATE {table} SET {col} = NULL WHERE jsonb_typeof({col}) = 'null'"
-            )
+            op.execute(f"UPDATE {table} SET {col} = NULL WHERE jsonb_typeof({col}) = 'null'")
 
 
 def downgrade() -> None: