debugger: Start on tabless design (#27837)

![image](https://github.com/user-attachments/assets/1cd54b70-5457-4c64-95bd-45a7055ea165)

Release Notes:

- N/A

---------

Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Co-authored-by: Anthony <anthony@zed.dev>

crates/project/src/debugger/dap_store.rs

@@ -48,6 +48,7 @@ use worktree::Worktree;
 
 pub enum DapStoreEvent {
     DebugClientStarted(SessionId),
+    DebugSessionInitialized(SessionId),
     DebugClientShutdown(SessionId),
     DebugClientEvent {
         session_id: SessionId,
@@ -862,6 +863,10 @@ fn create_new_session(
             }
         }
 
+        this.update(cx, |_, cx| {
+            cx.emit(DapStoreEvent::DebugSessionInitialized(session_id));
+        })?;
+
         Ok(session)
     });
     task