feat: add complete AI release intelligence MVP

[floppy522]

AI Release Intelligence MVP + portfolio package

This PR delivers the deterministic GitHub-native release-readiness MVP and a
reviewable portfolio package for product, architecture, security, operations,
evaluation, and technical-decision review.

Final revision

• Head: b16563ab3705dbe82fc303960580be5cbeb9a922
• Base: main
• Status: ready for review

Portfolio deliverables

Five portfolio documents:

• Product case
• Architecture
• Threat model
• Operations runbook
• Benchmark evidence

Three architecture decisions:

• ADR 0001: Deterministic readiness core
• ADR 0002: Modular monolith
• ADR 0003: Fingerprinted human decisions

Three real deterministic-UI screenshots are embedded in the README:

• release setup;
• NEEDS_DECISION advisory evidence;
• READY after a documented accepted-risk decision.

Verification evidence

• Seeder contract: 52 passed on the final local package tree.
• CI run 33248881303:
  completed/success; all six jobs passed, including Playwright and Docker smoke.
• Task 2 PostgreSQL persistence run 33248881307:
  completed/success.
• PR feat: add complete AI release intelligence MVP #2: head matches the final revision; open, ready for review, and mergeable against
  main.

Verified synthetic demo

The public
demo repository
contains fictional evidence only. Final verification covers:

• six managed branches;
• four milestone issues;
• three merged pull requests;
• successful blocking-suite evidence;
• intentional advisory failure that produces NEEDS_DECISION before a human
  decision.

Demo topology/workflow evidence:

• release workflow run
• successful blocking migration job
• release operations issue

Evidence boundaries and limitations

• The demo and benchmark evidence are synthetic.
• External adoption and willingness to pay are unvalidated.
• The 30–60 minute manual-review baseline is experience-based, not measured.
• Human-versus-tool time savings and production-scale performance are not yet
  measured.
• The MVP supports one repository, one milestone, and one candidate branch;
  human risk acceptance remains a governance decision.

Review gate

The user explicitly approved Ready for review and Squash and merge after
the final green release gate.