use codex instructions by default

Support OpenAI-style stream toggle with SSE output

Update README: tools, direct backend, current model names

Fix direct Codex backend: headers, stream parsing, and tool continuation

Add gptel-codex-request-with-tools workaround for tool continuation bug

Fix auth account_id extraction and serve command parsing

Fix gptel-codex.el: reorganize and fix bugs

Use LOG_LEVEL env var for log level control

Use log/slog with proper log levels

Prepare for public release

Add Chrome User-Agent to Codex API requests

Fix random byte generation for PKCE

Add pure elisp gptel-codex backend with OAuth auth

Add auto-detect mode and callback server for auth flow

Initial chatgpt-proxy for gptel