ChatCrystal v0.5.3

Settings Model Discovery

• Added model-list discovery to the local Settings page for both LLM and Embedding configuration.
• Added a searchable fetched-model picker while keeping the model field manually editable.
• Added provider discovery support for Ollama, OpenAI-compatible endpoints, OpenAI, Anthropic, Google, and Custom providers; Azure returns an unsupported-provider message in this first version.
• Added POST /api/config/models so the server fetches model lists with saved or newly entered provider credentials instead of exposing third-party API keys to the browser.
• Marked cloud mode as unsupported for model discovery and surfaced the limitation in Settings.
• Added local browser-origin checks for model discovery proxying, plus structured errors for missing credentials, endpoint failures, auth failures, timeouts, and parse failures.
• Added regression coverage for model discovery services, routes, client API normalization, Settings wiring, and i18n copy.