ems-core v1.0.0: Standard EMS platform core

Shared backend + frontend for multi-customer EMS deployments.
- 12 enterprise modules: quota, cost, charging, maintenance, analysis, etc.
- 120+ API endpoints, 37 database tables
- Customer config mechanism (CUSTOMER env var + YAML config)
- Collectors: Modbus TCP, MQTT, HTTP API, Sungrow iSolarCloud
- Frontend: React 19 + Ant Design + ECharts + Three.js
- Infrastructure: Redis cache, rate limiting, aggregation engine

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

frontend/public/devices/water_meter.svg

@@ -0,0 +1,41 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="400" height="300" viewBox="0 0 400 300">
+  <defs>
+    <linearGradient id="bg" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#1a1a2e;stop-opacity:1" />
+      <stop offset="100%" style="stop-color:#16213e;stop-opacity:1" />
+    </linearGradient>
+  </defs>
+  <rect width="400" height="300" fill="url(#bg)" rx="12"/>
+  <!-- Meter body -->
+  <rect x="110" y="30" width="180" height="220" rx="10" fill="#f3f4f6" stroke="#d1d5db" stroke-width="2"/>
+  <!-- Screen -->
+  <rect x="130" y="50" width="140" height="60" rx="6" fill="#1f2937" stroke="#374151" stroke-width="1"/>
+  <!-- LCD display -->
+  <text x="200" y="82" text-anchor="middle" fill="#22c55e" font-family="monospace" font-size="24" font-weight="bold">1847.5</text>
+  <text x="260" y="82" text-anchor="end" fill="#22c55e" font-family="monospace" font-size="12">kWh</text>
+  <text x="140" y="65" fill="#6b7280" font-family="monospace" font-size="10">正向有功总</text>
+  <!-- Status LEDs -->
+  <circle cx="145" cy="125" r="4" fill="#22c55e"/>
+  <circle cx="160" cy="125" r="4" fill="#ef4444" opacity="0.3"/>
+  <circle cx="175" cy="125" r="4" fill="#eab308" opacity="0.3"/>
+  <text x="190" y="128" fill="#6b7280" font-family="Arial" font-size="9">运行</text>
+  <!-- Buttons -->
+  <circle cx="150" cy="155" r="10" fill="#e5e7eb" stroke="#9ca3af" stroke-width="1"/>
+  <circle cx="200" cy="155" r="10" fill="#e5e7eb" stroke="#9ca3af" stroke-width="1"/>
+  <circle cx="250" cy="155" r="10" fill="#e5e7eb" stroke="#9ca3af" stroke-width="1"/>
+  <text x="150" y="158" text-anchor="middle" fill="#6b7280" font-size="8" font-family="Arial">▲</text>
+  <text x="200" y="158" text-anchor="middle" fill="#6b7280" font-size="8" font-family="Arial">OK</text>
+  <text x="250" y="158" text-anchor="middle" fill="#6b7280" font-size="8" font-family="Arial">▼</text>
+  <!-- Terminal block -->
+  <rect x="130" y="190" width="140" height="40" rx="4" fill="#e5e7eb" stroke="#d1d5db"/>
+  <g fill="#374151">
+    <circle cx="150" cy="210" r="6" />
+    <circle cx="175" cy="210" r="6" />
+    <circle cx="200" cy="210" r="6" />
+    <circle cx="225" cy="210" r="6" />
+    <circle cx="250" cy="210" r="6" />
+  </g>
+  <!-- Label -->
+  <text x="200" y="272" text-anchor="middle" fill="#00d4ff" font-family="Arial, sans-serif" font-size="20" font-weight="bold">智能电表</text>
+  <text x="200" y="292" text-anchor="middle" fill="#6b7280" font-family="Arial, sans-serif" font-size="12">Smart Power Meter</text>
+</svg>