Add xAI's Grok as a new web_search provider alongside Brave and Perplexity.
Uses the xAI /v1/responses API with tools: [{type: "web_search"}].
Configuration:
- tools.web.search.provider: "grok"
- tools.web.search.grok.apiKey or XAI_API_KEY env var
- tools.web.search.grok.model (default: grok-4-1-fast)
- tools.web.search.grok.inlineCitations (optional, embeds markdown links)
Returns AI-synthesized answers with citations similar to Perplexity.
Adds support for Brave Search API's freshness parameter to filter results
by discovery time:
- 'pd' - Past 24 hours
- 'pw' - Past week
- 'pm' - Past month
- 'py' - Past year
- 'YYYY-MM-DDtoYYYY-MM-DD' - Custom date range
Useful for cron jobs and monitoring tasks that need recent results.
Note: Perplexity provider ignores this parameter (Brave only).
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🤖 AI-assisted: This PR was created with Claude (Opus). Lightly tested via
build script. The change follows existing patterns for optional parameters
(country, search_lang, ui_lang).