Add an endpoint to clear an instance's console buffer

Fixes #299

Add an endpoint to clear an instance's console buffer by clearing the circular buffer within the global app state buffer.

* **core/src/lib.rs**
  - Add a method `clear_console_buffer` to the `AppState` struct to clear the console buffer for a specific instance.

* **core/src/handlers/events.rs**
  - Add a new function `clear_console_buffer` to handle the request to clear the console buffer.
  - Add a new route `/instance/:uuid/console/clear` to handle the request to clear the console buffer.

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/Lodestone-Team/lodestone/issues/299?shareId=XXXX-XXXX-XXXX-XXXX).

core/src/handlers/events.rs

@@ -287,12 +287,37 @@ async fn console_stream_ws(
     }
 }
 
+pub async fn clear_console_buffer(
+    axum::extract::State(state): axum::extract::State<AppState>,
+    AuthBearer(token): AuthBearer,
+    Path(uuid): Path<InstanceUuid>,
+) -> Result<Json<()>, Error> {
+    let requester = state
+        .users_manager
+        .read()
+        .await
+        .try_auth(&token)
+        .ok_or_else(|| Error {
+            kind: ErrorKind::Unauthorized,
+            source: eyre!("Token error"),
+        })?;
+    if !requester.can_perform_action(&UserAction::ClearConsoleBuffer(uuid.clone())) {
+        return Err(Error {
+            kind: ErrorKind::PermissionDenied,
+            source: eyre!("You don't have permission to clear the console buffer"),
+        });
+    }
+    state.clear_console_buffer(&uuid).await;
+    Ok(Json(()))
+}
+
 pub fn get_events_routes(state: AppState) -> Router {
     Router::new()
         .route("/events/:uuid/stream", get(event_stream))
         .route("/events/:uuid/buffer", get(get_event_buffer))
         .route("/events/search", get(get_event_search))
         .route("/instance/:uuid/console/stream", get(console_stream))
         .route("/instance/:uuid/console/buffer", get(get_console_buffer))
+        .route("/instance/:uuid/console/clear", get(clear_console_buffer))
         .with_state(state)
 }

core/src/lib.rs

@@ -133,6 +133,10 @@ impl AppState {
             });
         }
     }
+
+    pub async fn clear_console_buffer(&self, uuid: &InstanceUuid) {
+        self.console_out_buffer.lock().await.remove(uuid);
+    }
 }
 
 async fn restore_instances(