feat: privacy-respecting analytics

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/routes/stats.ts

@@ -0,0 +1,19 @@
+import { Hono } from 'hono'
+import { getPublicStats } from '../engine/analytics.js'
+
+export const statsRouter = new Hono()
+
+// GET /public — aggregate stats for last 30 days, no PII
+statsRouter.get('/public', (c) => {
+  const days = Math.min(parseInt(c.req.query('days') || '30'), 90)
+  const rows = getPublicStats(days)
+
+  // Group by date for easier consumption
+  const byDate: Record<string, Record<string, number>> = {}
+  for (const row of rows) {
+    if (!byDate[row.date]) byDate[row.date] = {}
+    byDate[row.date][row.metric] = row.value
+  }
+
+  return c.json({ stats: byDate })
+})