Photo verification for chore completion

[Wikid82]

Why

For some chores (e.g. "clean your room"), a parent may want visual proof before points are awarded rather than trusting a checkbox.

Proposed approach

• Add an optional "requires photo" flag per chore
• On completion, prompt for a photo (camera capture works best from an installed PWA, PWA foundation: installable app (manifest + service worker) #32); store locally on disk (consistent with the SQLite-file self-hosted philosophy — no S3/object storage dependency)
• Completion sits in a pending-approval state until an admin approves the photo; notify the approver via Web Push (Web Push notifications #39) if available, in-app otherwise

Depends on

#32 (PWA foundation) for camera capture. Benefits from but does not require #39 (Web Push).

Acceptance criteria

• A chore can be flagged as requiring photo verification
• Completing it prompts for a photo and holds points pending admin approval
• Photos are stored on local disk, not a third-party service