#12469: feat(tools): add Querit (querit.ai) as web_search provider

Description: This PR adds Querit as a new search engine provider for OpenClaw. This PR replaces #2156 About Querit: Querit is an emerging search engine service that offers a free tier of 1,000 requests per month. Changes: - Added Querit search tool implementation. - Updated configuration to support Querit API keys and settings. - Updated docs. <img width="3558" height="1692" alt="image" src="https://github.com/user-attachments/assets/b710678d-e66d-4567-b4dd-a1a284bc11f9" /> <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR adds a new `web_search` provider (`querit`) alongside Brave/Perplexity/Grok, extends config types + runtime zod schema to accept `tools.web.search.provider = "querit"` and `tools.web.search.querit.apiKey` (with `QUERIT_API_KEY` env fallback), and updates docs to describe Querit setup and selection. The main integration point is `src/agents/tools/web-search.ts`, where the provider switch now includes a Querit POST request and maps results into the existing `web_search` result shape (title/url/description/siteName) with caching. <h3>Confidence Score: 3/5</h3> - This PR is close to mergeable but has a security-relevant issue in web_search output handling. - Most changes are straightforward config/docs updates, but Querit search results are returned without the external-content wrapping used elsewhere, weakening prompt-injection defenses for tool output. - src/agents/tools/web-search.ts <!-- greptile_other_comments_section --> _{(3/5) Reply to the agent's comments like "Can you suggest a fix for this @greptileai?" or ask follow-up questions!} <!-- /greptile_comment -->