Initial commit: Price Hunter — self-hosted price comparison engine

Complete application scaffolding with:
- Backend: Node.js + Fastify + sql.js (SQLite)
- Frontend: SvelteKit + Tailwind CSS
- Scraper engine with parallel fan-out, rate limiting, cheerio-based parsing
- Store management with CSS selector config and per-store test pages
- Docker setup for single-command deployment

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

src/server/routes/health.ts

@@ -0,0 +1,37 @@
+import type { FastifyPluginAsync } from 'fastify';
+import fs from 'node:fs';
+import { config } from '../config.js';
+import { getDatabase } from '../db/connection.js';
+
+function queryOne(sql: string, params: any[] = []): any | undefined {
+  const db = getDatabase();
+  const stmt = db.prepare(sql);
+  if (params.length) stmt.bind(params);
+  let result: any;
+  if (stmt.step()) {
+    result = stmt.getAsObject();
+  }
+  stmt.free();
+  return result;
+}
+
+export const healthRoutes: FastifyPluginAsync = async (app) => {
+  app.get('/health', async () => {
+    const storeCount = queryOne('SELECT COUNT(*) as count FROM stores')?.count ?? 0;
+    const enabledCount = queryOne('SELECT COUNT(*) as count FROM stores WHERE enabled = 1')?.count ?? 0;
+
+    let dbSizeBytes = 0;
+    try {
+      const stats = fs.statSync(config.databasePath);
+      dbSizeBytes = stats.size;
+    } catch {
+      // DB file may not exist yet
+    }
+
+    return {
+      status: 'ok',
+      stores: { total: storeCount, enabled: enabledCount },
+      database: { sizeBytes: dbSizeBytes, sizeMB: Math.round(dbSizeBytes / 1024 / 1024 * 100) / 100 },
+    };
+  });
+};