Initial commit: COPILOT D6 Flutter keyboard controller

Flutter web app replacing legacy WPF CCTV surveillance keyboard controller.
Includes wall overview, section view with monitor grid, camera input,
PTZ control, alarm/lock/sequence BLoCs, and legacy-matching UI styling.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

config/keyboards.json.template

@@ -0,0 +1,69 @@
+{
+  "$schema": "./keyboards.schema.json",
+  "version": "1.0",
+  "description": "Keyboard configuration for PRIMARY/STANDBY election",
+
+  "keyboards": [
+    {
+      "id": "KB-001",
+      "name": "Control Room 1",
+      "location": "Main Control Room",
+      "priority": 100,
+      "canBePrimary": true,
+      "canBeStandby": true,
+      "network": {
+        "address": "192.168.1.101",
+        "coordinationPort": 8090
+      }
+    },
+    {
+      "id": "KB-002",
+      "name": "Control Room 2",
+      "location": "Main Control Room",
+      "priority": 90,
+      "canBePrimary": true,
+      "canBeStandby": true,
+      "network": {
+        "address": "192.168.1.102",
+        "coordinationPort": 8090
+      }
+    },
+    {
+      "id": "KB-003",
+      "name": "Security Station",
+      "location": "Security Office",
+      "priority": 50,
+      "canBePrimary": false,
+      "canBeStandby": true,
+      "network": {
+        "address": "192.168.1.103",
+        "coordinationPort": 8090
+      }
+    }
+  ],
+
+  "election": {
+    "heartbeatIntervalMs": 2000,
+    "heartbeatTimeoutMs": 6000,
+    "electionTimeoutMs": 10000,
+    "minKeyboardsForQuorum": 1
+  },
+
+  "coordination": {
+    "primaryWebSocketPort": 8090,
+    "stateSync": {
+      "enabled": true,
+      "intervalMs": 1000
+    }
+  },
+
+  "degradedMode": {
+    "description": "Features available when no PRIMARY/STANDBY is online",
+    "viewerConnectLive": true,
+    "ptzControl": true,
+    "ptzLocking": false,
+    "sequences": false,
+    "sharedState": false,
+    "alarmDisplay": "local"
+  }
+}