Persist Codex 0.152 project trust in live qualification

[KeyffMS]

Summary

Apply the precision-v2 finding to the real C01-C16 qualification harness without changing product hook semantics or the release gate.

Runtime trust

• C06/C08/C09 now run with a disposable isolated CODEX_HOME;
• project trust is persisted in that home as [projects."<absolute-path>"] trust_level = "trusted";
• targeted probes no longer pass project trust through -c/--config and no longer use --ignore-user-config;
• each probed cwd/worktree is trusted dynamically and isolated-home cleanup plus auth fingerprint preservation are enforced.

C13

• ephemeral remains first and now uses its own isolated, persistently trusted CODEX_HOME;
• the known Codex 0.152 collab spawn failed: no thread with id condition is always treated as a transport blocker even if SubagentStart/context fired before the failure;
• only that known blocker enables the existing non-ephemeral fallback;
• fallback uses persisted trust, an explicit home-scoped fixture_agent declaration, project-scoped SubagentStart hook, cleanup checks, and auth immutability checks.

Regression protection

• new executable unit tests verify persisted trust is idempotent, invalid CLI trust is absent, --ignore-user-config is removed only in the targeted wrapper, dynamic cwd trust is persisted, CODEX_HOME is restored, and C13 fallback remains narrowly gated;
• product hooks, sandbox policy, approval policy, C01-C16 gate semantics, and normal user TokenBudget behavior are unchanged.