fix: Restore techStack variable in SystemInfo to fix build error

docs: Update About section with Multi-Model Agent Consensus details

fix: Robust seed data protection and enhanced diagnostic counters

fix: Add missing backend dependencies and implement connection debugger

feat: Final auto-sync logic, manual seed button and REW branding

style: Rename System to About and update REW agency URL

feat: Add System tab with REW credits and fix DB seeding