docs: prepare maintainer validation

[builtbyhuy]

Summary

• add an outcome-separated maintainer validation ledger
• qualify only two first-contact routes and explicitly skip promotional issue outreach
• bind outreach language to exact source preparation and immutable release evidence
• reconcile the stricter ten-downstream-workflow application gate

Current outcome state

• contacts: 0
• independent runs: 0
• retained required CI: 0
• unknown defects: 0
• application: HOLD

Verification

• CSV: 11 columns, 2 prepared rows, blank outcome fields
• npm test: 158 pass, 0 fail, 1 expected local strict skip
• independent review: PASS
• git diff --check