Add CSV upload panel for meters and readings

- Add CSV upload service with upsert logic for meters
- Add CSV upload routes (POST /csv-upload/meters, POST /csv-upload/readings)
- Add template download endpoints for CSV format
- Create standalone upload-panel React app on port 5174
- Support concentrator_serial lookup for meter creation

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

upload-panel/vite.config.ts

@@ -0,0 +1,21 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+import tailwindcss from "@tailwindcss/vite";
+
+export default defineConfig({
+  plugins: [
+    react({
+      jsxRuntime: 'automatic',
+    }),
+    tailwindcss(),
+  ],
+  server: {
+    host: true,
+    port: 5174,
+    allowedHosts: [
+      "localhost",
+      "127.0.0.1",
+      "panel.gestionrecursoshidricos.com"
+    ],
+  },
+});