Formatting: ruff line-length 100, kwarg-spacing passes, drop blank after short local imports (#6079)

Raise ruff line-length to 100 and extend the local pre-commit format pipeline (def-signature magic-comma normalization, short multi-line assert collapse, kwarg '=' spacing, blank-line-after-short-import removal, adjacent string-literal / f-string+plain merge, redundant-pass pruning). Every transform re-checks the file AST and is dropped if it would differ; the whole-repo reformat is verified AST-identical per file and idempotent.

scripts/verify_comment_only_diff.py

@@ -128,12 +128,15 @@ def _normalize_yaml_run_strings(obj: Any) -> Any:
     return obj
 
 
-def _walk_yaml_diff(b: Any, a: Any, prefix: str = "") -> None:
+def _walk_yaml_diff(
+    b: Any,
+    a: Any,
+    prefix: str = "",
+) -> None:
     """Print a path-keyed summary of the first structural / scalar diff."""
     if type(b) is not type(a):
         print(
-            f"     type-diff at {prefix or '/'}: "
-            f"{type(b).__name__} -> {type(a).__name__}",
+            f"     type-diff at {prefix or '/'}: " f"{type(b).__name__} -> {type(a).__name__}",
         )
         return
     if isinstance(b, dict):