fix: Resolve 61 critical linting errors

Fixed priority linting errors to improve code quality:

Critical Fixes:
- F821 (2 errors): Fixed undefined name 'original_result' in config_enhancer.py
- UP035 (2 errors): Removed deprecated typing.Dict and typing.Type imports
- F401 (27 errors): Removed unused imports and added noqa for availability checks
- E722 (19 errors): Replaced bare 'except:' with 'except Exception:'

Code Quality Improvements:
- SIM201 (4 errors): Simplified 'not x == y' to 'x != y'
- SIM118 (2 errors): Removed unnecessary .keys() in dict iterations
- E741 (4 errors): Renamed ambiguous variable 'l' to 'line'
- I001 (1 error): Sorted imports in test_bootstrap_skill.py

All modified areas tested and passing:
- test_scraper_features.py: 42 passed
- test_integration.py: 51 passed
- test_architecture_scenarios.py: 11 passed
- test_real_world_fastmcp.py: 19 passed (1 skipped)

Remaining linting errors: 249 (mostly code style suggestions like ARG002, F841, SIM102)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/skill_seekers/cli/utils.py

@@ -173,7 +173,7 @@ def validate_zip_file(zip_path: str | Path) -> tuple[bool, str | None]:
     if not zip_path.is_file():
         return False, f"Not a file: {zip_path}"
 
-    if not zip_path.suffix == ".zip":
+    if zip_path.suffix != ".zip":
         return False, f"Not a .zip file: {zip_path}"
 
     return True, None