Fix 5 defects found in v0.6.16 code review

[Copilot]

Code review of v0.6.15→v0.6.16 delta surfaced five defects across tools, LLM providers, and UI.

• EditFileError TypedDict incorrectly uses total=False — all fields become optional, but _serialize_edit_file_error unconditionally accesses error, message, path. Switched to NotRequired on matches only.

• _find_match_spans infinite loop on empty string — str.find("", n) returns n for any valid n, so start never advances. Added early-return guard. Caller validates today, but the private function was unprotected.

• edit_file missing exception handling — only tool method in LocalFilesystemRuntime without try/except wrapping. Unhandled OSError (ENOSPC, TOCTOU race) would crash the runtime. Added consistent error handling matching sibling methods.

• In-place message mutation causes instruction duplication on retry — OpenAICompatibleLLM._apply_prompt_provider_specific_structured_schema calls multipart_messages[-1].add_text(instructions), mutating the original. When _execute_with_retry retries, instructions accumulate. Fixed by deep-copying the last message before mutation, matching the Bedrock provider pattern:

  # Before (mutates caller's list on every retry)
  multipart_messages[-1].add_text(instructions)
  
  # After (isolated copy)
  last_copy = multipart_messages[-1].model_copy(deep=True)
  last_copy.add_text(instructions)
  multipart_messages = multipart_messages[:-1] + [last_copy]

• _normalize_reference_token returns "" instead of None — whitespace-only input returned empty string; callers checking is None missed the cancellation signal.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• astral.sh
  • Triggering command: /usr/bin/curl curl -LsSf REDACTED git conf�� --global _agent/mcp/helpers/content_helpe!.git cal/bin/git (dns block)
• releases.astral.sh
  • Triggering command: /home/REDACTED/.local/bin/uv uv run scripts/typecheck.py -main/dist/ripgrep/bin/linux-x64/rg conf�� unset --global /opt/pipx_bin/git credential.helpebash (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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Original prompt

review uncommitted changes for defects

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