Handle reset failure gracefully when squash produces no changes

The reset during early exit could throw if the worktree is already in a
conflicted state, masking the real "no changes" diagnostic.

src/commands/squash.ts

@@ -35,7 +35,7 @@ export async function action(branch: string) {
     const diff = await git.diffStaged(worktree)
 
     if (!diff.trim()) {
-      await git.resetSoft(originalHead, worktree)
+      await git.resetSoft(originalHead, worktree).catch(() => {})
       spin.fail("No changes after squash")
       process.exit(1)
     }