[Feature]: Ensure cursor:click event parity in export renderer

[crbender]

• I have searched the existing issues

Is your feature request related to a problem?

Yes. Extensions relying on cursor:click need consistent event behavior across preview and export.

Describe the solution you'd like

Ensure cursor:click events are emitted in export rendering with parity to preview timing semantics.

Describe alternatives you've considered

Relying on extension-side inference without explicit export events. Rejected, leads to inconsistent behavior and edge cases.

Additional context

This is required for click-sound extensions that listen to cursor:click and trigger sound playback from that event.

Acceptance criteria

1. Export path emits cursor:click for interaction points used during render.
2. Event timing aligns to export timeline timestamps.
3. Existing cursor visual behavior does not regress.
4. Integration test validates preview/export event parity for representative click stream.

[crbender]

Tracking under parent issue #572 for sequencing and rollout context.