fix: SearXNG search provider improvements and bug fixes

[norci]

Related

Follow-up to #920

Changes

Bug Fixes

• Fix bundled.rs: remove non-existent reference to ../bundled/searxng/SKILL.md
• Remove unused page parameter from search_searxng

Features

• Add list_searxng_categories tool to agent tool lists
• Consolidate web-search skill with SearXNG integration

Documentation

• Update bundled skills count from 61 to 60
• Move SearXNG section earlier in web-search SKILL.md for better visibility
• Add SearXNG to web search providers in docs and tool definitions

Refactoring

• Streamline searxng skill - remove web-search duplication, add runtime integration

Configuration

The SearXNG configuration is simple — only url is required:

[web]
search_provider = "searxng"

[web.searxng]
url = "https://your-searxng-instance.com"

Note: Unlike other providers (Brave, Tavily), SearXNG does not have a max_results field. The docs in configuration.md are already correct.

Files Changed

39 files, +1245/-346 lines

[norci]

PR #920 was created by the agent without my permission and has some flaws.

This is the complete implementation. I have run it on my local machine and the agent can now correctly use searxng for searches.

[norci]

CI Status Update

Fixed

• ✅ Format — Applied to fix formatting issues introduced by this PR's changes

Pre-existing failures (not related to this PR)

The following CI checks are failing on the main branch as well and are unrelated to the SearXNG changes in this PR:

• ❌ Security Audit — RUSTSEC-2026-0049 in rustls-webpki 0.102.8 (needs upgrade to >=0.103.10). Dependency chain: rumqttc 0.24.0 → openfang-channels
• ❌ Clippy / Check / Test — Blocked by the same security vulnerability in the dependency tree

Recent main branch merges (#753, #877, #881) all have the same CI failures, confirming these are pre-existing issues that should be addressed in a separate PR (e.g., upgrading rumqttc or rustls-webpki).