chore: lint and format entire codebase

Run ruff check --fix: remove unused imports (F401), fix f-strings
without placeholders (F541), remove unused variables (F841), fix
duplicate dict key (F601).

Run isort --profile black: normalize import ordering across all files.

Run ruff format: apply consistent formatting (black-compatible) to
all 58 Python files.

3 intentional E402 remain (imports after require_yaml() must execute
after yaml is available).

scripts/scraper/targets/__init__.py

@@ -2,6 +2,7 @@
 
 Auto-detects *_targets_scraper.py files and exposes their scrapers.
 """
+
 from __future__ import annotations
 
 import importlib