- Add BUILTIN_MODELS for OpenAI (GPT-5.4/Mini/5.3-Codex), Google (Gemini 3 Pro/Flash, 2.5 Pro/Flash), and GitHub Copilot
- Add resolve_model_id_for_sdk() and resolve_aux_model() to route prefixed model IDs (cx/, gc/, gh/) through 9Router translator
- Add GET /agents/models endpoint returning available models based on live 9Router connection state
- Enable ENABLE_TOOL_SEARCH=auto for all providers so non-Claude models get full tool access (23 built-in + all MCPs)
- Add thinking block streaming support (ThinkingBlock in stream handler + AssistantMessage) for reasoning models
- Fix Gemini 3 thought-signature errors: use skip_thought_signature_validator per Google docs
- Fix WebSearch blocked_domains/allowed_domains empty-list rejection on Anthropic API
- Fix browser_agent text_parts UnboundLocalError on non-Claude models
- Fix auxiliary LLM calls (title gen, group meta, dashboard naming, view builder, browser agent) via resolve_aux_model
- Add Codex OAuth callback listener on port 1455 for ChatGPT Plus subscription connect
- Route Gemini OAuth through system browser since Google blocks embedded webviews
- Override Electron popup user-agent for OAuth
- Fix duplicate OAuth callback with idempotent completed_oauth tracking
- Fix Settings modal tab routing and stale warning banner
- Add API key inputs for OpenAI, Google, and OpenRouter
- Add MCP warning banner when selecting non-Claude model with many tools
- Force session fork on cross-provider model switch to prevent transcript corruption
- Disable GitHub Copilot subscription card (9Router poll issue, marked preview)
- Delete dead CopilotProvider import and unused CopilotAuthButton component