[bencode]

What

A deployment can switch web search to DeepSeek's Search & Fetch tools:

GAMMA_SEARCH_PROVIDER=deepseek   → search and page reading use DeepSeek, with DEEPSEEK_API_KEY
GAMMA_SEARCH_PROVIDER unset      → Tavily when TAVILY_API_KEY is set, as before

The public deployment already sets DEEPSEEK_API_KEY for chat, so the provider is named explicitly rather than inferred from the key; it stays on Tavily.

How

• web-search/provider.ts: the Tavily client becomes a shared serviceClient; deepseekSearch and deepseekExtract sit beside the Tavily pair. A hit's snippet is DeepSeek's model-oriented summary, falling back to snippet; date becomes published. A query is cut to DeepSeek's 128-character limit instead of being refused. Both extractors share the title trimming and the size cap.
• main.ts: picks the services from GAMMA_SEARCH_PROVIDER; an unknown value, or deepseek without a key, stops the server at start.
• GAMMA_SEARCH_PROXY now applies to Tavily only; DeepSeek is reached directly.
• compose.production.yml forwards GAMMA_SEARCH_PROVIDER; docs/self-hosting.md and the README describe it.

Checked

• pnpm check: Biome, TypeScript and all unit tests pass. Two web integration tests failed once under the full parallel run; test:integration alone passes 85/85, and this branch touches no web code.
• Against the live API: a Chinese query returned hits with summaries; Fetch read github.com/bencode as Markdown, and answered 404 for a page it could not reach, which surfaces as the route's usual 502.