assistant2: Order agent profiles in the order they are defined in settings (#27255)

This PR updates the ordering of the agent profiles in the tool selector
to respect the order they are defined in in the settings instead of
sorting them alphabetically.

This gives the user more control, and allows them to order the profiles
as they desire.

Release Notes:

- N/A

crates/assistant_settings/src/agent_profile.rs

@@ -1,20 +1,20 @@
 use std::sync::Arc;
 
-use collections::HashMap;
 use gpui::SharedString;
+use indexmap::IndexMap;
 
 /// A profile for the Zed Agent that controls its behavior.
 #[derive(Debug, Clone)]
 pub struct AgentProfile {
     /// The name of the profile.
     pub name: SharedString,
-    pub tools: HashMap<Arc<str>, bool>,
+    pub tools: IndexMap<Arc<str>, bool>,
     #[allow(dead_code)]
-    pub context_servers: HashMap<Arc<str>, ContextServerPreset>,
+    pub context_servers: IndexMap<Arc<str>, ContextServerPreset>,
 }
 
 #[derive(Debug, Clone)]
 pub struct ContextServerPreset {
     #[allow(dead_code)]
-    pub tools: HashMap<Arc<str>, bool>,
+    pub tools: IndexMap<Arc<str>, bool>,
 }