refactor: modularize codebase and add DB workload multiplier

- Split monolithic index.ts (2370 lines) into modular structure:
  - src/handlers/ for route handlers
  - src/utils.ts for shared utilities
  - src/config.ts for configuration
  - src/types.ts for TypeScript definitions

- Add DB workload multiplier for smarter database resource calculation:
  - Heavy (analytics, logs): 0.3x multiplier
  - Medium-heavy (e-commerce, transactional): 0.5x
  - Medium (API, SaaS): 0.7x
  - Light (blog, portfolio): 1.0x

- Fix tech_specs with realistic vcpu_per_users values (150+ technologies)
- Fix "blog" matching "log" regex bug
- Update documentation to reflect new architecture

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/handlers/health.ts

@@ -0,0 +1,20 @@
+/**
+ * Health check endpoint handler
+ */
+
+import { jsonResponse } from '../utils';
+
+/**
+ * Health check endpoint
+ */
+export function handleHealth(corsHeaders: Record<string, string>): Response {
+  return jsonResponse(
+    {
+      status: 'ok',
+      timestamp: new Date().toISOString(),
+      service: 'server-recommend',
+    },
+    200,
+    corsHeaders
+  );
+}