Add three new K6 load test scripts to cover previously untested API surfaces:
- search-advanced.js: Combined geo + text + filter queries, paginated deep
search, and sort variations against /search and /search/geo (300 peak VUs)
- admin.js: Moderation queue CRUD, bulk moderation, dashboard stats, audit
logs, and user management endpoints (50 peak VUs)
- mcp.js: MCP server discovery, SSE connection, property-search tool calls,
valuation/batch-valuation, and feature extraction (120 peak VUs)
Also updates README with new suite documentation, per-suite custom thresholds,
and adds the new suites to the CI workflow_dispatch selector.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
