context_store: Refactor state management (#29910)

Because we instantiated `ContextServerManager` both in `agent` and
`assistant-context-editor`, and these two entities track the running MCP
servers separately, we were effectively running every MCP server twice.

This PR moves the `ContextServerManager` into the project crate (now
called `ContextServerStore`). The store can be accessed via a project
instance. This ensures that we only instantiate one `ContextServerStore`
per project.

Also, this PR adds a bunch of tests to ensure that the
`ContextServerStore` behaves correctly (Previously there were none).

Closes #28714
Closes #29530

Release Notes:

- N/A

crates/project/src/project.rs

@@ -1,6 +1,7 @@
 pub mod buffer_store;
 mod color_extractor;
 pub mod connection_manager;
+pub mod context_server_store;
 pub mod debounced_delay;
 pub mod debugger;
 pub mod git_store;
@@ -23,6 +24,7 @@ mod project_tests;
 mod direnv;
 mod environment;
 use buffer_diff::BufferDiff;
+use context_server_store::ContextServerStore;
 pub use environment::{EnvironmentErrorMessage, ProjectEnvironmentEvent};
 use git_store::{Repository, RepositoryId};
 pub mod search_history;
@@ -182,6 +184,7 @@ pub struct Project {
     client_subscriptions: Vec<client::Subscription>,
     worktree_store: Entity<WorktreeStore>,
     buffer_store: Entity<BufferStore>,
+    context_server_store: Entity<ContextServerStore>,
     image_store: Entity<ImageStore>,
     lsp_store: Entity<LspStore>,
     _subscriptions: Vec<gpui::Subscription>,
@@ -845,6 +848,7 @@ impl Project {
         ToolchainStore::init(&client);
         DapStore::init(&client, cx);
         BreakpointStore::init(&client);
+        context_server_store::init(cx);
     }
 
     pub fn local(
@@ -865,6 +869,9 @@ impl Project {
             cx.subscribe(&worktree_store, Self::on_worktree_store_event)
                 .detach();
 
+            let context_server_store =
+                cx.new(|cx| ContextServerStore::new(worktree_store.clone(), cx));
+
             let environment = cx.new(|_| ProjectEnvironment::new(env));
             let toolchain_store = cx.new(|cx| {
                 ToolchainStore::local(
@@ -965,6 +972,7 @@ impl Project {
                 buffer_store,
                 image_store,
                 lsp_store,
+                context_server_store,
                 join_project_response_message_id: 0,
                 client_state: ProjectClientState::Local,
                 git_store,
@@ -1025,6 +1033,9 @@ impl Project {
             cx.subscribe(&worktree_store, Self::on_worktree_store_event)
                 .detach();
 
+            let context_server_store =
+                cx.new(|cx| ContextServerStore::new(worktree_store.clone(), cx));
+
             let buffer_store = cx.new(|cx| {
                 BufferStore::remote(
                     worktree_store.clone(),
@@ -1109,6 +1120,7 @@ impl Project {
                 buffer_store,
                 image_store,
                 lsp_store,
+                context_server_store,
                 breakpoint_store,
                 dap_store,
                 join_project_response_message_id: 0,
@@ -1267,6 +1279,8 @@ impl Project {
         let image_store = cx.new(|cx| {
             ImageStore::remote(worktree_store.clone(), client.clone().into(), remote_id, cx)
         })?;
+        let context_server_store =
+            cx.new(|cx| ContextServerStore::new(worktree_store.clone(), cx))?;
 
         let environment = cx.new(|_| ProjectEnvironment::new(None))?;
 
@@ -1360,6 +1374,7 @@ impl Project {
                 image_store,
                 worktree_store: worktree_store.clone(),
                 lsp_store: lsp_store.clone(),
+                context_server_store,
                 active_entry: None,
                 collaborators: Default::default(),
                 join_project_response_message_id: response.message_id,
@@ -1590,6 +1605,10 @@ impl Project {
         self.worktree_store.clone()
     }
 
+    pub fn context_server_store(&self) -> Entity<ContextServerStore> {
+        self.context_server_store.clone()
+    }
+
     pub fn buffer_for_id(&self, remote_id: BufferId, cx: &App) -> Option<Entity<Buffer>> {
         self.buffer_store.read(cx).get(remote_id)
     }