feat(kitchenhub): searchable ingredient picker for recipe editor

[BrendenWalker]

Summary

• Replace the KitchenHub recipe ingredient <select> with a searchable picker modal (search, OK/Cancel, Escape/backdrop close).
• Match existing KitchenHub dialog patterns (overlay card, primary/secondary buttons, portal to document.body).
• Add unit tests for filter, confirm, and cancel flows.

Test plan

• Open a recipe, click Edit, click Select ingredient… — modal opens with search focused
• Type a partial name/details string and confirm the list narrows
• Select an ingredient and click OK — button shows the chosen label
• Double-click a row or Enter with a single match — selection confirms and closes
• Cancel / Escape / backdrop click — closes without changing selection
• Add ingredient still requires unit and excludes ingredients already on the recipe
• npx vitest run in kitchenhub/frontend passes