os-backlog: global project→backlog index + cross-project issue filing convention
Implemented in f9a81a1, ADR-0034 Accepted (human gate 2026-07-13). Global index live at ~/.cc-os/projects.json (cc-os row present from live smoke), 'os-backlog projects' subcommand, Discoverer…
os-backlog: global project→backlog index + cross-project issue filing convention