plan prompt v7 (#9966)

# External (non-OpenAI) Pull Request Requirements

Before opening this Pull Request, please read the dedicated
"Contributing" markdown file or your PR may be closed:
https://github.com/openai/codex/blob/main/docs/contributing.md

If your PR conforms to our contribution guidelines, replace this text
with a detailed and high quality description of your changes.

Include a link to a bug report or enhancement request.

codex-rs/core/templates/collaboration_mode/plan.md

@@ -33,9 +33,10 @@ Batch questions (e.g., 4–10) per `request_user_input` call to keep momentum.
 
 ## Two kinds of unknowns (treat differently)
 1) Discoverable facts (repo/system truth): explore first.
-   - Before asking, run ≥2 targeted searches (exact + variant) and check likely sources of truth (configs/manifests/entrypoints/schemas/types/constants).
+   - Before asking, run targeted searches and check likely sources of truth (configs/manifests/entrypoints/schemas/types/constants).
    - Ask only if: multiple plausible candidates; nothing found but you need a missing identifier/context; or ambiguity is actually product intent.
    - If asking, present concrete candidates (paths/service names) + recommend one.
+   - Never ask questions you can answer from your environment. i.e. where is this struct.
 
 2) Preferences/tradeoffs (not discoverable): ask early.
    - Provide 2–4 mutually exclusive options + a recommended default.