feat: add notes field to ingredient editor

Add editable notes field to ingredients in the unified recipe editor, allowing users to add preparation notes like "sifted", "room temperature", etc.

Changes:
- Added notes input field below amount/unit/name inputs in UnifiedEditRecipe.tsx
- Styled notes field with italic, gray text to indicate optional nature
- Added placeholder text with examples (e.g., sifted, room temperature)
- Field uses existing ingredient.notes field from database schema
- Notes are saved with other ingredient data via updateIngredient function

The notes field is displayed with reduced font size and lighter styling to differentiate from required ingredient fields.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/web/src/pages/UnifiedEditRecipe.tsx

@@ -881,6 +881,15 @@ function UnifiedEditRecipe() {
                         onMouseDown={(e) => e.stopPropagation()}
                       />
                     </div>
+                    <input
+                      type="text"
+                      className="ingredient-notes-input"
+                      value={ingredient.notes || ''}
+                      onChange={(e) => updateIngredient(index, 'notes', e.target.value)}
+                      placeholder="Notes (e.g., sifted, room temperature)"
+                      draggable={false}
+                      onMouseDown={(e) => e.stopPropagation()}
+                    />
                   </div>
 
                   <button