fix: replace bare except clauses with except Exception in llmcore.py

[Kailigithub]

Summary

Replace 17 bare except: clauses in llmcore.py with except Exception: to follow Python best practices and pass ruff E722 lint checks.

Changes

All bare except: in llmcore.py replaced with except Exception::

• Line 32: reload_mykeys() fallback
• Line 165/185: _stream Anthropic tool JSON parsing
• Lines 197, 203: _try_parse_tool_args() JSON parsing fallback
• Lines 222, 271: SSE stream line JSON parsing
• Lines 328, 343: OpenAI response tool call JSON parsing
• Line 364: retry-after header parsing
• Line 377: HTTP response body extraction
• Line 871: tool call JSON extraction in _parse_json_tool_calls
• Lines 887, 895: _parse_text_tool_calls XML/JSON fallback
• Lines 919, 922, 924: tryparse() multi-stage JSON parsing

Verification

• python3 -m py_compile llmcore.py passes
• ruff check llmcore.py --select E722 reports all checks passed