feat: add inline chart support for notes

- Add NoteChart component using Recharts (bar, line, area, pie, radar, funnel, gauge)
- Add generate_chart and insert_chart_in_note AI tools
- Add chart code block support in MarkdownContent (```chart ... ```)
- Support JSON and simple data formats (label: value)
- Add i18n translations for chart features

Chart syntax examples:
- JSON: ```chart {"type":"bar","data":[{"label":"A","value":10}]} ```
- Simple: ```chart\nbar\nSales Data\nJan: 120\nFeb: 150\n```

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

memento-note/lib/ai/tools/chart.tool.ts

@@ -0,0 +1,117 @@
+/**
+ * Chart Tool for Notes
+ * Allows AI to generate inline charts from note data
+ */
+
+import { tool } from 'ai'
+import { z } from 'zod'
+import { toolRegistry } from './registry'
+
+// Chart generation tool - inserts chart as markdown code block
+toolRegistry.register({
+  name: 'generate_chart',
+  description: 'Generate an inline chart from data and insert it into a note as markdown. The chart will be rendered directly in the note.',
+  isInternal: true,
+  buildTool: (ctx) =>
+    tool({
+      description: `Generate an inline chart from data and return it as a markdown code block that can be inserted into a note.
+
+Available chart types:
+- "bar": Vertical bar chart
+- "horizontal-bar": Horizontal bar chart
+- "line": Line chart for trends over time
+- "area": Area chart (filled line)
+- "pie": Pie/donut chart for proportions
+- "radar": Radar chart for comparing multiple dimensions
+- "funnel": Funnel chart for stages/conversions
+- "gauge": Gauge/meter for a single value
+
+Data format: Array of objects with "label" (string) and "value" (number).
+
+IMPORTANT:
+- Extract data from the note content when possible
+- Keep labels short (max 20 characters)
+- Round values to reasonable precision (max 2 decimal places)
+- For time series, use short date formats (Jan, Feb, Mar or 2023, 2024)
+- Maximum 12 data points for readability
+- The output will be rendered as a visual chart in the note`,
+      inputSchema: z.object({
+        chartType: z.enum(['bar', 'horizontal-bar', 'line', 'area', 'pie', 'radar', 'funnel', 'gauge']).describe('Type of chart to generate'),
+        title: z.string().optional().describe('Optional title for the chart'),
+        data: z.array(z.object({
+          label: z.string().describe('Label for the data point (e.g., month name, category)'),
+          value: z.number().describe('Numeric value for the data point'),
+        })).describe('Array of data points with label and value'),
+        insertLocation: z.enum(['append', 'prepend', 'replace']).default('append').describe('Where to insert the chart in the note'),
+        targetNoteId: z.string().optional().describe('Optional: specific note ID to update. If not provided, use the current note.'),
+      }),
+      execute: async ({ chartType, title, data, insertLocation, targetNoteId }) => {
+        try {
+          // Generate the markdown code block for the chart
+          const chartData = data.map(d => `${d.label}: ${d.value}`).join('\n')
+          const chartMarkdown = `\`\`\`chart
+${chartType}${title ? `\n${title}` : ''}
+${chartData}
+\`\`\`\n`
+
+          return {
+            success: true,
+            chartMarkdown,
+            chartType,
+            dataPointCount: data.length,
+            message: `Chart generated with ${data.length} data points. Insert this markdown into the note.`,
+          }
+        } catch (e: any) {
+          return { success: false, error: `Chart generation failed: ${e.message}` }
+        }
+      },
+    }),
+})
+
+// Quick chart insert tool - directly updates a note with a chart
+toolRegistry.register({
+  name: 'insert_chart_in_note',
+  description: 'Insert a chart directly into a note. Reads the note, extracts relevant data, generates a chart, and updates the note content.',
+  isInternal: true,
+  buildTool: (ctx) =>
+    tool({
+      description: `Insert a chart directly into a note. This tool will:
+1. Read the current note content
+2. Extract relevant data from the note (sales, metrics, comparisons, etc.)
+3. Generate an appropriate chart type based on the data
+4. Insert the chart markdown into the note
+
+Use this when the user says "make a chart", "create a graph", "visualize this data", etc.
+
+Choose the chart type based on the data:
+- Use "bar" for comparing values across categories (default)
+- Use "horizontal-bar" when labels are long
+- Use "line" or "area" for time series or trends
+- Use "pie" for showing proportions/percentages
+- Use "radar" for comparing multiple attributes
+- Use "funnel" for stages or conversion data
+- Use "gauge" for progress/KPI (single value)`,
+      inputSchema: z.object({
+        noteId: z.string().describe('The note ID to read and update'),
+        chartHint: z.string().optional().describe('Optional hint about what to chart (e.g., "sales by month", "comparison of products")'),
+        insertLocation: z.enum(['append', 'prepend', 'before-section', 'after-section']).default('append').describe('Where to insert the chart'),
+        sectionMarker: z.string().optional().describe('For before-section/after-section: the heading text to find (e.g., "## Sales Data")'),
+      }),
+      execute: async ({ noteId, chartHint, insertLocation, sectionMarker }) => {
+        try {
+          // We'll return the instructions for the AI to format the chart
+          // The actual note update will be done by note_find_and_update or note_update
+          return {
+            success: true,
+            instructions: 'Generate a chart markdown block using the generate_chart tool, then use note_update or note_find_and_update to insert it into the note.',
+            noteId,
+            chartHint,
+            insertLocation,
+            sectionMarker,
+          }
+        } catch (e: any) {
+          return { success: false, error: `Failed to prepare chart insertion: ${e.message}` }
+        }
+      },
+    }),
+})