Add edit and delete controls for video owners on detail page

[kelleyglenn]

Summary

Video owners should be able to edit or delete their own submissions from the video detail page. The video-service API already supports PUT /videos/{id} and DELETE /videos/{id} with ownership checks.

Acceptance Criteria

• "Edit" button visible to the video owner on the detail page
• Edit mode allows changing: amendments, participants, video date, location
• YouTube-fetched fields (title, description, channel, thumbnail) are not editable
• "Delete" button visible to the video owner
• Delete shows a confirmation dialog before calling the API
• Successful delete redirects to the map page with a confirmation toast
• Edit/delete only available when video status is not APPROVED (per API ownership rules)
• Moderators/Admins can also delete any video

References

• Video-service PUT /videos/{id} — update with ownership check
• Video-service DELETE /videos/{id} — delete with ownership check