agent: Refresh the profile selector and modal design (#29816)

- [x] Separate MCP servers from tools in the profile customization modal
view
- [x] Group MCP tools in the MCP picker and add a heading
- [x] Separate bult-in profiles from custom ones in the dropdown
selector
- [x] Separate bult-in profiles from custom ones in the modal
- [ ] Enable looping through items via keybinding without opening the
dropdown (will be done on a follow-up PR)
- [ ] Stretch: Focus on the currently active item upon opening the
dropdown (will be done on a follow-up PR)

Release Notes:

- N/A

---------

Co-authored-by: Bennet Bo Fenner <53836821+bennetbo@users.noreply.github.com>
Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: Bennet Bo Fenner <bennet@zed.dev>

crates/assistant_settings/src/agent_profile.rs

@@ -5,6 +5,41 @@ use indexmap::IndexMap;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
+pub mod builtin_profiles {
+    use super::AgentProfileId;
+
+    pub const WRITE: &str = "write";
+    pub const ASK: &str = "ask";
+    pub const MANUAL: &str = "manual";
+
+    pub fn is_builtin(profile_id: &AgentProfileId) -> bool {
+        profile_id.as_str() == WRITE || profile_id.as_str() == ASK || profile_id.as_str() == MANUAL
+    }
+}
+
+#[derive(Default)]
+pub struct GroupedAgentProfiles {
+    pub builtin: IndexMap<AgentProfileId, AgentProfile>,
+    pub custom: IndexMap<AgentProfileId, AgentProfile>,
+}
+
+impl GroupedAgentProfiles {
+    pub fn from_settings(settings: &crate::AssistantSettings) -> Self {
+        let mut builtin = IndexMap::default();
+        let mut custom = IndexMap::default();
+
+        for (profile_id, profile) in settings.profiles.clone() {
+            if builtin_profiles::is_builtin(&profile_id) {
+                builtin.insert(profile_id, profile);
+            } else {
+                custom.insert(profile_id, profile);
+            }
+        }
+
+        Self { builtin, custom }
+    }
+}
+
 #[derive(Debug, PartialEq, Eq, Hash, Clone, Serialize, Deserialize, JsonSchema)]
 pub struct AgentProfileId(pub Arc<str>);