[diagnostics] show diagnostics earlier in workflow (#13604)

<img width="591" height="243" alt="Screenshot 2026-03-05 at 10 17 06 AM"
src="https://github.com/user-attachments/assets/84a6658b-6017-4602-b1f8-2098b9b5eff9"
/>

- show feedback earlier
- preserve raw literal env vars (no trimming, sanitizing, etc.)

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__feedback_upload_consent_popup.snap

@@ -8,6 +8,10 @@ expression: popup
     • codex-logs.log
     • codex-connectivity-diagnostics.txt
 
+  Connectivity diagnostics
+    - OPENAI_BASE_URL is set and may affect connectivity.
+      - OPENAI_BASE_URL = hello
+
 › 1. Yes  Share the current Codex session logs with the team for
           troubleshooting.
   2. No

codex-rs/tui/src/chatwidget/tests.rs

@@ -7290,7 +7290,12 @@ async fn feedback_upload_consent_popup_snapshot() {
         chat.app_event_tx.clone(),
         crate::app_event::FeedbackCategory::Bug,
         chat.current_rollout_path.clone(),
-        true,
+        &codex_feedback::feedback_diagnostics::FeedbackDiagnostics::new(vec![
+            codex_feedback::feedback_diagnostics::FeedbackDiagnostic {
+                headline: "OPENAI_BASE_URL is set and may affect connectivity.".to_string(),
+                details: vec!["OPENAI_BASE_URL = hello".to_string()],
+            },
+        ]),
     ));
 
     let popup = render_bottom_popup(&chat, 80);
@@ -7305,7 +7310,12 @@ async fn feedback_good_result_consent_popup_includes_connectivity_diagnostics_fi
         chat.app_event_tx.clone(),
         crate::app_event::FeedbackCategory::GoodResult,
         chat.current_rollout_path.clone(),
-        true,
+        &codex_feedback::feedback_diagnostics::FeedbackDiagnostics::new(vec![
+            codex_feedback::feedback_diagnostics::FeedbackDiagnostic {
+                headline: "OPENAI_BASE_URL is set and may affect connectivity.".to_string(),
+                details: vec!["OPENAI_BASE_URL = hello".to_string()],
+            },
+        ]),
     ));
 
     let popup = render_bottom_popup(&chat, 80);