docs: record native desktop adoption attempt and remaining gates

[veil-chow-fyaic]

Outcome

Installed and removed the diagnostic through official Codex and ZCode management paths. Tested two pre-installation conversations: prior signup decision retained, but no native diagnostic call or verifiable probe marker obtained. Existing-session adoption remains open.

Evidence discipline

• Codex follow-up used a host delegation, not manual UserPromptSubmit; exact hook trust was not completed.
• ZCode catalog format corrected; generic hook rows are not credited as probe output.
• Both temporary installs removed; source/catalogs and disposable conversations retained.
• No business conversations, restarts, private transcript files or private control interfaces used.

Checks

10 probe/identity tests passed; 130 repository Markdown files plus the experiment guide lint cleanly; diff check passed. Independent internal evidence review passed.

Refs #156; does not close the desktop adoption or delivery gates.