5e856b4fde
The existing normalizeToolArgSchemas only applies to omo plugin tools (via tool-registry.ts), but MCP server tool schemas bypass this sanitization entirely. MCP schemas with contentEncoding/contentMediaType cause Gemini 400 errors. Add sanitizeJsonSchema() to strip unsupported keywords from MCP tool inputSchema before serialization in formatMcpCapabilities. Fixes #2200 Supersedes #2666