fix(chart): show correct chart type in previews

- Use NoteChart directly with props instead of NoteChartFromCode
- Remove markdown ticks from chartSuggestionToMarkdown output
- Export NoteChart component for direct use in previews

Now the 3 suggestions correctly show different chart types.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memento-note/components/rich-text-editor.tsx

@@ -291,18 +291,12 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
       setChartSuggestionsOpen(true)
     }, [editor])
 
-    const handleSelectChart = useCallback((markdown: string) => {
+    const handleSelectChart = useCallback((chartContent: string) => {
       if (!editor || !editor.isEditable) return
 
       try {
-        // Convert markdown chart to HTML format for TipTap
-        // Input: ```chart\nbar\nTitle\nlabel: value\n```
-        // Output: <pre><code class="language-chart">bar\nTitle\nlabel: value</code></pre>
-        const chartContent = markdown
-          .replace(/```chart\n?/gi, '')
-          .replace(/```$/gi, '')
-          .trim()
-
+        // chartContent is now raw content without markdown ticks
+        // Example: "bar\nTitle\nlabel: value"
         const htmlContent = `<pre><code class="language-chart">${chartContent}</code></pre>`
 
         // Insert the chart HTML at current position
@@ -321,7 +315,7 @@ export const RichTextEditor = forwardRef<RichTextEditorHandle, RichTextEditorPro
           }
         }
 
-        // Insert the chart as HTML (not markdown)
+        // Insert the chart as HTML
         editor.chain().focus().insertContent(htmlContent).run()
       } catch (error) {
         console.error('[handleSelectChart] Failed to insert chart:', error)