Show notifications on primary screen by default (#27665)

By default, agent notifications now display only on your primary screen.
You can optionally configure them to display on all screens (or not to
display at all).

Release Notes:

- N/A

crates/assistant_settings/src/assistant_settings.rs

@@ -26,6 +26,15 @@ pub enum AssistantDockPosition {
     Bottom,
 }
 
+#[derive(Copy, Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum NotifyWhenAgentWaiting {
+    #[default]
+    PrimaryScreen,
+    AllScreens,
+    Never,
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
 #[serde(tag = "name", rename_all = "snake_case")]
 pub enum AssistantProviderContentV1 {
@@ -74,7 +83,7 @@ pub struct AssistantSettings {
     pub default_profile: Arc<str>,
     pub profiles: IndexMap<Arc<str>, AgentProfile>,
     pub always_allow_tool_actions: bool,
-    pub notify_when_agent_waiting: bool,
+    pub notify_when_agent_waiting: NotifyWhenAgentWaiting,
 }
 
 impl AssistantSettings {
@@ -394,10 +403,10 @@ pub struct AssistantSettingsContentV2 {
     ///
     /// Default: false
     always_allow_tool_actions: Option<bool>,
-    /// Whether to show a popup notification when the agent is waiting for user input.
+    /// Where to show a popup notification when the agent is waiting for user input.
     ///
-    /// Default: true
-    notify_when_agent_waiting: Option<bool>,
+    /// Default: "primary_screen"
+    notify_when_agent_waiting: Option<NotifyWhenAgentWaiting>,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]