Implement incremental recording persistence and recording controls

[kalen-releasedgroup]

Summary

Make recording durable and controllable for real users instead of only demo flows.

Scope

• Persist recording progress incrementally.
• Implement pause, resume, stop, cancel, mark important, ignore noise, and inline notes.
• Enforce masking rules during capture and preview for sensitive fields.

Requirement Links

• FR-REC-007, FR-REC-008, FR-REC-010
• Sections 9.2, 12.3, 12.5
• Acceptance Criterion 6

Dependencies

• Event capture pipeline
• Artefact/security baseline

Exit Criteria

• Host failure does not imply total loss of long recordings.
• Recording controls work from the UI.
• Sensitive data is masked in persisted previews and recording views.