Clarify question handling in Default collaboration mode (#41448)

## What changed

- Allow `request_user_input` for optional questions that materially improve work quality.
- Continue with best judgment when the tool returns no answers.
- Keep permission requests, escalations, and other required input out of the tool; ask one concise plain-text question when progress cannot safely continue.
- Update the collaboration-mode preset test for the revised direct-question guidance.

GitOrigin-RevId: 8393621f0d8b59d8b164368ab7f2c8f4f6b3b14e

codex-rs/collaboration-mode-templates/templates/default.md

@@ -8,4 +8,12 @@ Your active mode changes only when new developer instructions with a different `
 
 Use the `request_user_input` tool only when it is listed in the available tools for this turn.
 
-In Default mode, strongly prefer making reasonable assumptions and executing the user's request rather than stopping to ask questions. If you absolutely must ask a question because the answer cannot be discovered from local context and a reasonable assumption would be risky, ask the user directly with a concise plain-text question. Never write a multiple choice question as a textual assistant message.
+In Default mode, strongly prefer making reasonable assumptions and executing the user's request rather than stopping to ask questions.
+
+Use the `request_user_input` tool only for optional questions where the answer would materially improve the quality of the work.
+
+If `request_user_input` returns no answers, continue with best judgment instead of asking again or treating the turn as blocked.
+
+Never use the `request_user_input` tool for permission requests or permission-related escalations.
+
+If explicit user input is required for another reason before progress can safely continue, do not use the `request_user_input` tool. Ask the user directly with one concise plain-text question instead. Never write a multiple choice question as a textual assistant message.

codex-rs/models-manager/src/collaboration_mode_presets_tests.rs

@@ -31,6 +31,6 @@ fn default_mode_instructions_replace_mode_names_placeholder() {
         "Use the `request_user_input` tool only when it is listed in the available tools"
     ));
     assert!(
-        default_instructions.contains("ask the user directly with a concise plain-text question")
+        default_instructions.contains("Ask the user directly with one concise plain-text question")
     );
 }