Add support for local LM Studio endpoints in Claude Code

[lklyne]

Summary

This PR adds support for using Claude Code with local, Anthropic-compatible endpoints (such as LM Studio 0.4.1+) in addition to the existing Anthropic API models (Opus, Sonnet, Haiku).

Key Changes

• New buildClaudeInvocation function: Extracted and refactored the Claude CLI invocation logic into a testable, reusable function that handles model selection, permissions, and local endpoint configuration
• Local model support: Added 'local' as a new FixModel option with configurable baseUrl, modelId, and authToken fields
• Environment variable routing: When using a local model, the function sets ANTHROPIC_BASE_URL, ANTHROPIC_AUTH_TOKEN, and ANTHROPIC_MODEL environment variables to point Claude Code's CLI at the local server
• UI enhancements: Added input fields in the Fix Settings panel for configuring local endpoint details (base URL, model ID, auth token) with sensible defaults for LM Studio
• Type safety improvements: Created FixConfigPatch type for partial config updates and updated all related type signatures
• Comprehensive test coverage: Added 6 new test cases covering Opus defaults, model-specific flags, permissions, local endpoint configuration, LM Studio defaults, and whitespace trimming

Implementation Details

• Local endpoint defaults to http://localhost:1234 (LM Studio default) with auth token lmstudio
• Configuration values are trimmed of whitespace before use
• The modelId parameter is optional; if not provided, the CLI won't receive a --model flag for local endpoints
• Preferences are persisted with the new local configuration fields
• All existing Anthropic API model behavior remains unchanged

https://claude.ai/code/session_01FKkE9D6dM7n5bPWaSKAVHr