chore: apply oxlint autofix (safe level)

Auto-fixed 102 warnings (6040 → 5938) across 57 files. Main categories:
- preserve-caught-error: add { cause: error } to re-thrown errors
- unicorn/no-array-reverse: .reverse() → .toReversed()
- unicorn/no-useless-fallback-in-spread: drop unnecessary ?? {} in spreads
- oxc/no-map-spread: rewrite object spread in .map() to Object.assign
- react-hooks/exhaustive-deps: trim module-level constants from dep arrays

Ran npm run format after to clean up whitespace from lint mutations.

packages/app/src/screens/new-workspace-screen.tsx

@@ -292,7 +292,7 @@ export function NewWorkspaceScreen({
         cwd: input.cwd,
         worktreeSlug: createNameId(),
         ...(input.attachments.length > 0 ? { attachments: input.attachments } : {}),
-        ...(checkoutRequest ?? {}),
+        ...checkoutRequest,
       };
     },
     [selectedItem],