Marcel
a4bde0953e
docs(c4): fix diagram 3c service layer and add missing 3e components
- diagram 3c: GroupController delegates to UserService (not groupRepo directly)
- diagram 3c: add TagService; TagController delegates to TagService (not tagRepo)
- diagram 3e: add DashboardController serving /api/dashboard/resume|pulse|activity
- diagram 3e: add StatsService; StatsController delegates to StatsService
Addresses blocker feedback from Markus, Felix, and Elicit in PR #448 review.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>