Add You.com search as a no-auth remote MCP entry in the integration catalog

Desired Behavior

Agent Canvas and OpenHands agents can connect to You.com web search as a no-auth remote MCP server, selected from the shared integration catalog like the existing search providers.

Today every web-search MCP entry in the catalog (tavily, exa, firecrawl, kagi) requires an API key, so a fresh install has no working web search until the user signs up with one of those providers. You.com exposes an anonymous free tier on its MCP endpoint (https://api.you.com/mcp?profile=free) that works with zero setup — a good zero-configuration option to offer alongside the keyed ones.

Acceptance Criteria

• integrations/catalog/youcom-search.json exists: shttp transport to the keyless free-tier endpoint, auth.strategy: none
• youcom-search added to the intentionally-public remote MCP ids in tests/test_catalogs.py
• integrations/catalog-index.js regenerated with npm run build:integrations
• Opt-in live smoke test (RUN_YOUCOM_MCP_LIVE=1) exercises you-search through the same create_mcp_tools stack the Agent Canvas probe uses
• Existing integrations, search defaults, and saved settings are untouched

Compare the existing search-provider entries in integrations/catalog/ and update tests/test_catalogs.py for the intentionally-public remote MCP ids. Add integrations/catalog/youcom-search.json with the specified endpoint and no-auth strategy, regenerate integrations/catalog-index.js with npm run build:integrations, and run the opt-in RUN_YOUCOM_MCP_LIVE=1 smoke test through create_mcp_tools without changing existing settings or defaults.