`[2026-09-18]` Worldtree's `env.sh` secrets are vaulted

Worldtree's env.sh secrets are vaulted — 10 entries under worldtree/ (gitea, matrix as/hs, openai, uv-index, vastblueai, wt-admin demo+personal, z-ai, zai). ⚠ Z_AI_API_KEY and ZAI_API_KEY are DIFFERENT keys despite the near-identical names (fp 26bde3fa vs a4884152). ANTHROPIC_API_KEY was empty and skipped.