fix: Force RichTextEditor to update with template data

## Issue:
- API returns data ✅
- Console shows template data ✅
- But form inputs remain empty ❌

## Root Cause:
RichTextEditor not re-rendering when template data loads

## Fixes:

### 1. Add Key Prop to Force Re-render ✅
```tsx
<RichTextEditor
  key={`editor-${eventId}-${channelId}`}  // Force new instance
  content={body}
  onChange={setBody}
  variables={variableKeys}
/>
```

- Key changes when route params change
- Forces React to create new editor instance
- Ensures fresh state with new template data

### 2. Improve RichTextEditor Sync Logic ✅
```tsx
useEffect(() => {
  if (editor && content) {
    const currentContent = editor.getHTML();
    if (content !== currentContent) {
      console.log("RichTextEditor: Updating content");
      editor.commands.setContent(content);
    }
  }
}, [content, editor]);
```

- Check if content actually changed
- Add logging for debugging
- Prevent unnecessary updates

## Expected Result:
1. Template data loads from API ✅
2. Subject input fills with default ✅
3. Body editor fills with default ✅
4. Variables populate dropdown ✅

Test by refreshing the page!

admin-spa/src/routes/Settings/Notifications/EditTemplate.tsx

@@ -298,6 +298,7 @@ export default function EditTemplate() {
                 />
               ) : (
                 <RichTextEditor
+                  key={`editor-${eventId}-${channelId}`}
                   content={body}
                   onChange={setBody}
                   placeholder={__('Enter notification message')}