v4.1.4: Framework-aware dead code precision and grep verification improvements

Fixed

• Honor project .gitignore during file discovery. Ignored worktrees, custom virtualenvs, and other excluded paths are no longer scanned
• Treat imperative framework entrypoints as live code instead of dead code:
  • Flask add_url_rule(...)
  • FastAPI add_api_route(...)
  • Starlette add_route(...) / add_websocket_route(...)
  • Sanic register_listener(...) / register_middleware(...)
• Treat pytest / Pluggy hook implementations (@pytest.hookimpl, @hookimpl) as live plugin entrypoints
• Grep cache saves now fail open on non-writable roots instead of aborting analysis
• skylos --llm now shows populated Problem: descriptions for dead code findings
• Dead code findings in --llm output now include rule IDs and severity levels
• Fixed Windows uvx skylos crash caused by litellm path length issues

Changed

• Static grep_verify now reuses .skylos/cache/grep_results.json across repeated local scans
• Phase 2b LLM audits now focus on high-signal files instead of scanning the full Python set
• Agent scans are faster on changed-file workflows, and fix generation is now opt-in
• litellm is now optional for core static analysis installs
• litellm is capped at <1.82.8 due to the known supply chain issue