Accept corrected delete trace file message

[liurenfeng94-ops]

Fixes a small message-name typo without breaking old callers.

The file manager now sends deleteTraceFile, and the shared schema/extension handler accept both the corrected name and the legacy deletTraceFile spelling. That keeps existing messages working while letting new code use the spelled-out name.

Validation:

• pnpm vitest run test/delete-trace-file-message.test.ts
• pnpm vitest run
• pnpm typecheck
• pnpm exec eslint .
• pnpm build

[github-actions]

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[liurenfeng94-ops]

Thanks — I reviewed the PR text again. The intent is just to move the UI and schema to the correctly spelled deleteTraceFile message while keeping deletTraceFile accepted for compatibility.