Review form swallows validation errors — no feedback on bad input #15
Description
The ReviewForm Svelte component calls actions.addReview() but doesn't handle the error case. If you submit with an empty name or no rating, nothing visible happens — the Zod validation fails server-side and the form just sits there.
We need to:
- Show inline error messages for each field
- Highlight fields that failed validation
- Handle the action error response and surface it to the user