refactor(status): Support batch and all changes discard functionality

The file discarding mechanism has been significantly refactored to improve handling of multi-file operations. Instead of processing discards on a per-file basis, the system now supports batch actions for selected files or reverting all tracked modifications simultaneously. This update centralizes complex discard logic into dedicated functions across the component suite.

- Updated state management and types to handle arrays of file changes.
- Added UI elements and handlers for discarding all staged/unstaged changes.
- Enhanced the confirmation dialog to display multiple discarded targets in a list view.

src/app.css

@@ -3188,6 +3188,23 @@
     align-items: center;
     gap: 6px;
   }
+  .discard-target-list {
+    display: grid;
+    gap: 4px;
+    max-height: 168px;
+    overflow: auto;
+    margin: 0;
+    padding: 0;
+    list-style: none;
+  }
+  .discard-target-list .discard-target {
+    max-height: none;
+  }
+  .discard-target-more {
+    padding: 2px 2px 0;
+    color: var(--color-ink-muted);
+    font-size: 12px;
+  }
   .discard-warning-text {
     color: #ffb8bf;
     font-weight: 650;