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/protocol/src/protocol.rs

@@ -1649,14 +1649,16 @@ pub struct SessionConfiguredEvent {
 }
 
 /// User's decision in response to an ExecApprovalRequest.
-#[derive(
-    Debug, Default, Clone, Copy, Deserialize, Serialize, PartialEq, Eq, Display, JsonSchema, TS,
-)]
+#[derive(Debug, Default, Clone, Deserialize, Serialize, PartialEq, Eq, Display, JsonSchema, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum ReviewDecision {
     /// User has approved this command and the agent should execute it.
     Approved,
 
+    /// User has approved this command and wants to add the command prefix to
+    /// the execpolicy allow list so future matching commands are permitted.
+    ApprovedAllowPrefix { allow_prefix: Vec<String> },
+
     /// User has approved this command and wants to automatically approve any
     /// future identical instances (`command` and `cwd` match exactly) for the
     /// remainder of the session.