OpenRouter OAuth integration: Offer to OAuth against OpenRouter if no model and keys are provided. Select OpenRouter default model based on free/paid tier status if `OPENROUTER_API_KEY` is set and no model is specified. Prioritize `gemini/gemini-2.5-pro-exp-03-25` if `GEMINI_API_KEY` is set, and `vertex_ai/gemini-2.5-pro-exp-03-25` if `VERTEXAI_PROJECT` is set, when no model is specified. Validate user-configured color settings on startup and warn/disable invalid ones. Warn at startup if `--stream` and `--cache-prompts` are used together, as cost estimates may be inaccurate. Boost repomap ranking for files whose path components match identifiers mentioned in the chat.

Change web scraping timeout from an error to a warning, allowing scraping to continue with potentially incomplete content. Left-align markdown headings in the terminal output, by Peter Schilling. Update edit format to the new model's default when switching models with `/model`, if the user was using the old model's default format. Add the `openrouter/deepseek-chat-v3-0324:free` model. Add `Ctrl-X Ctrl-E` keybinding to edit the current input buffer in an external editor, by Matteo Landi. Fix linting errors for…