v1.3.0 - unified command output

Consistent terminal output across all seven commands

Every command now shares one output style instead of each inventing its own:

• Rendered markdown, not code-fenced ASCII. /build and /status reports are now markdown tables; code fences are reserved for copyable content (commands, diffs, branches).
• One status-glyph set everywhere: ✅ pass/ready/approved · ❌ fail/blocked · ⚠️ warning/judgement/medium-risk · ⏭️ deferred/skipped/on-hold.
• A **Next:** footer on every command.
• House style documented in CONTRIBUTING.md so future commands stay consistent.

No behavioural change - output formatting only.

Full changelog: v1.2.0...v1.3.0