fix(run): 优化 Run／Debug 启动动画反馈 (#2087)

Clicking Run or Debug gave no feedback until a session existed, so a slow launch looked as if nothing had happened.

The widget now shows a spinner as soon as a launch is requested and keeps it through the session's starting state. Pending launches are tracked per configuration, so switching to one already running does not replay it.

Siblings covered: Stop stays available during startup, including the Java build and classpath step, and launches that fail, are cancelled or do nothing clear the spinner.

Co-authored-by: PLZY <[email protected]>

src/ui/Feedback.module.css

@@ -33,6 +33,9 @@
   color: var(--fg-muted);
   animation: spin 0.9s linear infinite;
 }
+.spokes {
+  animation: spin 1s steps(8, end) infinite;
+}
 @keyframes spin {
   to {
     transform: rotate(360deg);
@@ -207,4 +210,7 @@
   .spinner {
     animation-duration: 2.4s;
   }
+  .spokes {
+    animation: none;
+  }
 }