feat: Add JSON definitions for menu, password input, and popover components

- Introduced `menu.json` for menu component structure with bindings for trigger and content.
- Created `password-input.json` for password input handling visibility and value changes.
- Added `popover.json` for popover component with trigger and content bindings.

feat: Implement custom hooks for UI interactions

- Added `useAccordion` for managing accordion state with single/multiple item support.
- Created `useBindingEditor` for managing bindings in a dynamic editor.
- Implemented `useCopyState` for clipboard copy functionality with feedback.
- Developed `useFileUpload` for handling file uploads with drag-and-drop support.
- Introduced `useFocusState` for managing focus state in components.
- Created `useImageState` for handling image loading and error states.
- Added `useMenuState` for managing menu interactions and item clicks.
- Implemented `usePasswordVisibility` for toggling password visibility.
- Developed `usePopoverState` for managing popover visibility and interactions.

feat: Add constants and interfaces for JSON UI components

- Introduced constants for sizes, placements, styles, and object-fit handling.
- Created interfaces for various components including Accordion, Binding Editor, Copy Button, Data Source Editor, File Upload, and more.
- Added type definitions for menu items, popover props, and other UI elements to enhance type safety and maintainability.

docs/JSON_CONSTANTS.md

@@ -0,0 +1,107 @@
+# JSON Constants Migration Guide
+
+## Overview
+
+This document tracks the extraction of hardcoded constants from JSON component definitions into the centralized constants folder.
+
+## Status
+
+### ✅ Constants Folder Created
+Location: `src/lib/json-ui/constants/`
+
+Files:
+- `sizes.ts` - Size-related constants
+- `placements.ts` - Positioning constants
+- `styles.ts` - CSS class constants
+- `object-fit.ts` - Image object-fit constants
+- `index.ts` - Centralized exports
+
+### 📋 Constants Found in JSON Files
+
+#### CopyButton (`copy-button.json`)
+```javascript
+// Line 11: sizeStyles
+const sizeStyles = { sm: 'p-1', md: 'p-2', lg: 'p-3' }
+// → BUTTON_SIZES
+
+// Lines 25, 39: iconSize (duplicated)
+const iconSize = { sm: 12, md: 16, lg: 20 }
+// → ICON_SIZES
+```
+
+#### Popover (`popover.json`)
+```javascript
+// Line 39: placementStyles
+const placementStyles = {
+  top: 'bottom-full mb-2 left-1/2 -translate-x-1/2',
+  bottom: 'top-full mt-2 left-1/2 -translate-x-1/2',
+  left: 'right-full mr-2 top-1/2 -translate-y-1/2',
+  right: 'left-full ml-2 top-1/2 -translate-y-1/2'
+}
+// → POPOVER_PLACEMENTS
+```
+
+#### Image (`image.json`)
+```javascript
+// Line 51: Dynamic object-fit (uses template literal)
+return `${base} ${opacity} object-${fit}`
+// Could use OBJECT_FIT_CLASSES but requires transform refactor
+```
+
+## Recommendations
+
+### Option 1: Keep Inline (Current Approach)
+**Pros:**
+- No changes to component-renderer needed
+- Self-contained JSON definitions
+- Easy to understand transforms
+
+**Cons:**
+- Duplication of constants
+- Harder to maintain consistency
+- Magic strings scattered across files
+
+### Option 2: Import Constants in Hooks
+**Pros:**
+- Hooks can use TypeScript constants
+- No changes to JSON structure needed
+- Immediate benefit for custom hooks
+
+**Cons:**
+- Only helps with hook-based logic
+- Still have duplication in JSON transforms
+
+### Option 3: Add Constants to Transform Context (Future)
+**Pros:**
+- Eliminates duplication entirely
+- Type-safe constants usage
+- Easier to update global styles
+
+**Cons:**
+- Requires component-renderer changes
+- More complex transform evaluation
+- Migration effort for existing JSON files
+
+## Recommended Next Steps
+
+1. **Short term:** Use constants in custom hooks (Option 2)
+   - Hooks can import from `@/lib/json-ui/constants`
+   - Reduce duplication in hook code
+
+2. **Medium term:** Document best practices
+   - Add examples of using constants
+   - Create migration guide for new components
+
+3. **Long term:** Enhanced transform context (Option 3)
+   - Update component-renderer to expose constants
+   - Migrate existing JSON files to use constants
+   - Remove inline const statements
+
+## Files to Potentially Update
+
+When migrating to Option 3:
+- `copy-button.json` - sizeStyles, iconSize
+- `popover.json` - placementStyles
+- `menu.json` - May have similar patterns
+- `file-upload.json` - May have size constants
+- Any future components using similar patterns