discoverability wave

Feature wave (2026-09-08):

• f0rge spec verb + starter spec on init (#35)
• per-verb help everywhere, parse-error try-hints (#36/#37/#43)
• issue edit --milestone/--label/--assignee; --body-file (#43/#44)
• wiki put bare stdin; issue list labels column; registries sorted
• 1000B contract; AGENTS.md refreshed