chore(config) Rename config setting to personality (#10314)

## Summary
Let's make the setting name consistent with the SlashCommand!

## Testing
- [x] Updated tests

codex-rs/tui/src/app.rs

@@ -1875,7 +1875,7 @@ impl App {
                 let profile = self.active_profile.as_deref();
                 match ConfigEditsBuilder::new(&self.config.codex_home)
                     .with_profile(profile)
-                    .set_model_personality(Some(personality))
+                    .set_personality(Some(personality))
                     .apply()
                     .await
                 {
@@ -2325,7 +2325,7 @@ impl App {
     }
 
     fn on_update_personality(&mut self, personality: Personality) {
-        self.config.model_personality = Some(personality);
+        self.config.personality = Some(personality);
         self.chat_widget.set_personality(personality);
     }
 

codex-rs/tui/src/chatwidget.rs

@@ -3244,7 +3244,7 @@ impl ChatWidget {
         };
         let personality = self
             .config
-            .model_personality
+            .personality
             .filter(|_| self.config.features.enabled(Feature::Personality))
             .filter(|_| self.current_model_supports_personality());
         let op = Op::UserTurn {
@@ -3880,10 +3880,7 @@ impl ChatWidget {
     }
 
     fn open_personality_popup_for_current_model(&mut self) {
-        let current_personality = self
-            .config
-            .model_personality
-            .unwrap_or(Personality::Friendly);
+        let current_personality = self.config.personality.unwrap_or(Personality::Friendly);
         let personalities = [Personality::Friendly, Personality::Pragmatic];
         let supports_personality = self.current_model_supports_personality();
 
@@ -5184,7 +5181,7 @@ impl ChatWidget {
 
     /// Set the personality in the widget's config copy.
     pub(crate) fn set_personality(&mut self, personality: Personality) {
-        self.config.model_personality = Some(personality);
+        self.config.personality = Some(personality);
     }
 
     /// Set the model in the widget's config copy and stored collaboration mode.