Clear exclusive action if branch not found

Fixes issue reported through discord where start commit button is 
disabled.

Author: mtsgrd

apps/desktop/src/components/StackView.svelte

@@ -224,6 +224,25 @@
 		}
 	});
 
+	// Clear exclusive action if branch cannot be found.
+	// TODO: We must be able to express this better..
+	$effect(() => {
+		const exclusiveAction = projectState.exclusiveAction.current;
+		if (exclusiveAction && branchesResult.current.data) {
+			setTimeout(() => {
+				if (exclusiveAction && branchesResult.current.data) {
+					if ('branchName' in exclusiveAction) {
+						const branchName = exclusiveAction.branchName;
+						if (branchName && !branchesResult.current.data.some((b) => b.name === branchName)) {
+							projectState.exclusiveAction.set(undefined);
+							console.warn('Exclusive action cleared');
+						}
+					}
+				}
+			}, 500);
+		}
+	});
+
 	const startCommitVisible = $derived(uncommittedService.startCommitVisible(stack.id));
 
 	function onerror(err: unknown) {