Improve site performance and stabilize project loading

[joyzoursky]

Summary

• optimize MCP heavy paths and add tool/request timing instrumentation
• improve runner claim-loop distribution and consolidate runner inventory polling
• reduce API/auth query round-trips on hot project and MCP routes
• split i18n locale payloads for lazy loading to reduce initial client payload
• collapse projects page bootstrap fetch waterfall into a single endpoint
• fix project test-case flashing by removing a fetch effect loop on /projects/[id]

Validation

• npm run --workspace @skytest/web lint
• npm run --workspace @skytest/web test
• npm run verify