Decouple agent reregistration from settings changes (#39528)

Fixes a `--release`-only bug in feature-flagged agents where the feature
flag isn't picked up in some situations (unless there was a settings
change to go with it - due to an early return when settings didn't
change).

Release Notes:

- N/A

crates/project/src/agent_server_store.rs

@@ -146,10 +146,6 @@ impl AgentServerStore {
 
     fn agent_servers_settings_changed(&mut self, cx: &mut Context<Self>) {
         let AgentServerStoreState::Local {
-            node_runtime,
-            fs,
-            project_environment,
-            downstream_client,
             settings: old_settings,
             ..
         } = &mut self.state
@@ -168,6 +164,29 @@ impl AgentServerStore {
             return;
         }
 
+        self.reregister_agents(cx);
+    }
+
+    fn reregister_agents(&mut self, cx: &mut Context<Self>) {
+        let AgentServerStoreState::Local {
+            node_runtime,
+            fs,
+            project_environment,
+            downstream_client,
+            settings: old_settings,
+            ..
+        } = &mut self.state
+        else {
+            debug_panic!("Non-local projects should never attempt to reregister. This is a bug!");
+
+            return;
+        };
+
+        let new_settings = cx
+            .global::<SettingsStore>()
+            .get::<AllAgentServersSettings>(None)
+            .clone();
+
         self.external_agents.clear();
         self.external_agents.insert(
             GEMINI_NAME.into(),
@@ -256,7 +275,7 @@ impl AgentServerStore {
         let feature_flags_subscription =
             cx.observe_flag::<feature_flags::CodexAcpFeatureFlag, _>(move |_enabled, cx| {
                 let _ = this_handle.update(cx, |this, cx| {
-                    this.agent_servers_settings_changed(cx);
+                    this.reregister_agents(cx);
                 });
             });
         let mut this = Self {

crates/project/src/project.rs

@@ -36,10 +36,11 @@ use dap::inline_value::{InlineValueLocation, VariableLookupKind, VariableScope};
 use task::Shell;
 
 use crate::{
-    agent_server_store::{AgentServerStore, AllAgentServersSettings},
+    agent_server_store::AllAgentServersSettings,
     git_store::GitStore,
     lsp_store::{SymbolLocation, log_store::LogKind},
 };
+pub use agent_server_store::{AgentServerStore, AgentServersUpdated};
 pub use git_store::{
     ConflictRegion, ConflictSet, ConflictSetSnapshot, ConflictSetUpdate,
     git_traversal::{ChildEntriesGitIter, GitEntry, GitEntryRef, GitTraversal},