whitelist command prefix integration in core and tui (#7033)

this PR enables TUI to approve commands and add their prefixes to an
allowlist:
<img width="708" height="605" alt="Screenshot 2025-11-21 at 4 18 07 PM"
src="https://github.com/user-attachments/assets/56a19893-4553-4770-a881-becf79eeda32"
/>

note: we only show the option to whitelist the command when 
1) command is not multi-part (e.g `git add -A && git commit -m 'hello
world'`)
2) command is not already matched by an existing rule

codex-rs/tui/src/history_cell.rs

@@ -409,6 +409,19 @@ pub fn new_approval_decision_cell(
                 ],
             )
         }
+        ApprovedAllowPrefix { .. } => {
+            let snippet = Span::from(exec_snippet(&command)).dim();
+            (
+                "✔ ".green(),
+                vec![
+                    "You ".into(),
+                    "approved".bold(),
+                    " codex to run ".into(),
+                    snippet,
+                    " and added its prefix to your allow list".bold(),
+                ],
+            )
+        }
         ApprovedForSession => {
             let snippet = Span::from(exec_snippet(&command)).dim();
             (