feat: initial brainstorming app — Nuxt 3 + SQLite + admin auth

Nuxt 3 app with:
- SQLite (better-sqlite3) for persistence
- Anonymous idea submission and voting
- Admin auth with session cookies
- AI analysis via Gemini API
- Nuxt UI components + Tailwind

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/api/votes/[id].post.ts

@@ -0,0 +1,19 @@
+import { createHash } from 'crypto'
+import db from '../../utils/db'
+
+export default defineEventHandler((event) => {
+  const id = getRouterParam(event, 'id')
+  const ip = getRequestIP(event, { xForwardedFor: true }) || 'unknown'
+  const voterHash = createHash('sha256').update(ip + ':' + id).digest('hex')
+
+  try {
+    db.prepare('INSERT INTO vote_log (idea_id, voter_hash) VALUES (?, ?)').run(id, voterHash)
+    db.prepare('UPDATE ideas SET votes = votes + 1 WHERE id = ?').run(id)
+  } catch {
+    // UNIQUE constraint = already voted
+    throw createError({ statusCode: 409, statusMessage: 'Already voted' })
+  }
+
+  const row = db.prepare('SELECT votes FROM ideas WHERE id = ?').get(id) as any
+  return { votes: row?.votes ?? 0 }
+})