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/tests/test_plex_jsonb_normalize.py

@@ -4,6 +4,7 @@ UPDATE statements against seeded rows (the migration itself is a no-op in the em
 
 Uses the DB lane (`db` fixture) — skipped when no Postgres is reachable.
 """
+
 from sqlalchemy import text
 
 from app.models import PlexLibrary, PlexShow
@@ -30,15 +31,25 @@ def test_scalar_null_normalized_array_preserved(db):
     db.commit()
     # Set a pre-0.53.1 JSONB scalar null on one, a genuine array on the other.
     db.execute(text("UPDATE plex_shows SET genres = 'null'::jsonb WHERE rating_key = 'null_row'"))
-    db.execute(text("""UPDATE plex_shows SET genres = '["Drama"]'::jsonb WHERE rating_key = 'array_row'"""))
+    db.execute(
+        text("""UPDATE plex_shows SET genres = '["Drama"]'::jsonb WHERE rating_key = 'array_row'""")
+    )
     db.commit()
-    assert db.scalar(text("SELECT jsonb_typeof(genres) FROM plex_shows WHERE rating_key='null_row'")) == "null"
+    assert (
+        db.scalar(text("SELECT jsonb_typeof(genres) FROM plex_shows WHERE rating_key='null_row'"))
+        == "null"
+    )
 
     for stmt in _NORMALIZE:
         db.execute(text(stmt))
     db.commit()
 
     # The scalar null is now SQL NULL (jsonb_typeof of SQL NULL is itself NULL, not 'null')...
-    assert db.scalar(text("SELECT genres IS NULL FROM plex_shows WHERE rating_key='null_row'")) is True
+    assert (
+        db.scalar(text("SELECT genres IS NULL FROM plex_shows WHERE rating_key='null_row'")) is True
+    )
     # ...and a real array is untouched.
-    assert db.scalar(text("SELECT jsonb_typeof(genres) FROM plex_shows WHERE rating_key='array_row'")) == "array"
+    assert (
+        db.scalar(text("SELECT jsonb_typeof(genres) FROM plex_shows WHERE rating_key='array_row'"))
+        == "array"
+    )