content: add Me&Me agent-native software best practice

[anchenqlw]

Cookbook contribution

Summary

• Content type: Best Practice
• Locale: en-US
• Target audience: Builders designing persistent Qoder Cloud Agent-powered products and governed software-evolution workflows.
• User problem and expected outcome: Show how to use one QCA Agent system as the user-facing product engine and a second QCA Creator Agent system to turn feedback and runtime evidence into bounded, reviewable, and verifiable software changes.

Sources and assets

• Public sources used: Me&Me public project and the production site Me&Me · 我&猫.
• Private author reference: An author-owned local project snapshot was inspected solely to understand implementation patterns; it is not a public source, and no local path or private material is included in this contribution.
• Asset owner and license: The project owner contributes meandme-hero.png, meandme-cloud-home.png, and meandme-self-evolution.png for this Cookbook contribution under CC BY 4.0. The Mermaid diagrams and submitted article prose are original to this contribution and are contributed under the same license.

Specialist review

• Product, code, architecture, security, or regulated-domain reviewer, when applicable: QCA architecture plus security/governance review is recommended because the article covers long-running identities, scoped tools, credentials, software-change authority, human gates, canary rollout, freeze, and rollback.

Validation

• npm run check: PASS — 49/49 tests; one content item with 0 errors and 0 warnings; relative links, catalog build, and preview build passed.
• Generated preview reviewed for the title, platform-generated TOC, three local images, three Mermaid diagrams, tables, production-domain link, and single author display.
• Both commits include a valid Signed-off-by trailer.

Author checklist

• I used exactly one author and no more than five approved tags.
• The article has at least three ## sections and no hand-written table of contents.
• I did not use GitHub Alerts, video, raw HTML, JavaScript, MDX, iframe, remote images, SVG, or interactive content.
• Images are local PNG, JPEG, or WebP files with meaningful alternative text and documented rights.
• The contribution contains no credentials, customer data, personal information, internal links, or unreleased capabilities.
• I ran npm run check and reviewed the generated preview.
• Every commit contains a Signed-off-by trailer.
• I understand that maintainer Merge to main is the publication event.