Add signed external office events

[iamlukethedev]

Summary

• Add signed POST /api/office/events and no-store GET /api/office/events for recent external office events.
• Persist a bounded recent-event list under the Claw3D state directory.
• Poll external office events from the office UI and merge them into the Ops Center activity stream.
• Trigger confetti for incoming external events with effect: "confetti".
• Document CLAW3D_OFFICE_EVENTS_SECRET and add route coverage for signatures and validation.

Testing

• npm run test -- --run tests/unit/officeEventsRoute.test.ts tests/unit/operationsCenterPanel.test.ts tests/unit/stateAnimationMappingsEditor.test.tsx tests/unit/studioSettings.test.ts tests/unit/officeEventTriggers.test.ts
• npm run typecheck
• npm run smoke:dev-server
• Browser walkthrough with CLAW3D_OFFICE_EVENTS_SECRET=test-secret: posted a signed HubSpot-style deal.closed event and verified Deal closed: Automotive account signed. appears in Ops Center with zero captured browser console errors.

external_office_event_ops.webm
External office event in Ops Center

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