Refine Release 1 product model messaging

[smota]

Summary

Refines Release 1 product messaging away from a narrow reviewability lens toward consistency, manageability, durable evidence, and the opinionated/extensible SDLC baseline.

Implemented issues

Implements #141
Refs #142
Refs #143
Refs #144
Refs #145
Refs #146

Related issues

Complements the website revamp in C:/Code/movetheneedle/site/agent-sdlc and prior issue record alignment for #141-#146.

Workflow evidence

Workflow-status comment: exception: PR body records this docs messaging refinement.

Handover comments: exception: single-session implementation with council feedback.

Role-pass summary:

• Council input: product/design/IA review identified overuse of “reviewable”, over-centering GitHub as product identity, and missing opinionated SDLC baseline framing.
• Implementation: README now explains durable evidence, manageable role flow, human authority, baseline workflow, and adopter extension policy.

Validation evidence:

• pnpm test passed: 23 files / 147 tests.

Agent review

• Implemented by: pi
• Launcher: pi
• Executor: pi-parent
• Transport: local-cli
• Delegation boundary: current-session
• Model / runtime: gpt-5.5 / pi
• Review: self-review
• Workflow profile: standard
• Merge owner: human/operator
• Mode: single-agent
• Self-review disclosure: Same session implemented and reviewed; change is docs-only and backed by council feedback.

CI-equivalent validation

• Status: passed
  Commands:
• pnpm prettier --write README.md docs/agentflow-in-5-minutes.md docs/get-started.md docs/sdlc-definition.md
• pnpm test

Follow-up issues

None.

Out of scope

Website repository changes are committed separately in movetheneedle/site/agent-sdlc.