[Phase 5.2] Build dashboard with feedback metrics

[Andreas-Froyland]

Goal

Overview page when an org admin logs in. At-a-glance stats and recent activity.

Depends on: #19 (org management) - need orgs/projects before you can show metrics

Metrics cards

• Total feedback — across all projects
• Open feedback — status: open or in_progress
• Total votes — sum of all votes across projects
• This week — new feedback items created in the last 7 days

Activity feed

• Recent events in reverse chronological order:
  • "User X created feedback: [title]"
  • "Feedback [title] received 5 upvotes"
  • "Status changed: [title] → Done"
  • "GitHub issue #42 linked to [title]" (Phase 4)
• Paginated (show last 20, load more)

Project overview

• If org has multiple projects, show a card per project:
  • Project name
  • Open feedback count
  • Most upvoted open item (quick link)

Notes

• Metrics are computed from the DB (no separate analytics store for MVP)
• Refresh on page load (no real-time updates for MVP)
• Keep it simple and fast - this is the landing page