Merge main into 0.2.2.1 to resolve conflicts

Main had VP #735 hotfix commits that were also on dev. All conflicts
resolved by keeping 0.2.2.1 (superset of main). Verified: 2098 backend
tests pass, frontend builds clean, no conflict markers remain.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>