Include mts and cts files in realtime metrics

[liurenfeng94-ops]

Adds .mts and .cts source files to the realtime metrics file filter.

The current filter only includes .ts and .tsx, so TypeScript projects using native ESM/CJS source extensions are skipped. Declaration files are still excluded, including .d.ts, .d.mts, and .d.cts.

Validation:

• pnpm vitest run test/test-files.test.ts
• pnpm vitest run
• pnpm typecheck
• pnpm exec eslint .
• pnpm build

[github-actions]

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[liurenfeng94-ops]

Thanks — I rewrote the summary to be plain and specific. The change is just widening the realtime-metrics file filter to include .mts and .cts while still excluding declaration files.