Add configurable deployment system with VPN and Tor support

Features:
- Hidden config.json in assets for per-deployment customization
- Configure target URL, app name, and branding
- Optional WireGuard VPN with auto-connect
- Optional Tor routing via Orbot
- Custom theme colors
- Configuration-driven app behavior

Configuration file location: app/src/main/assets/config.json
Example configuration: config.example.json

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

config.example.json

@@ -0,0 +1,45 @@
+{
+  "_comment": "SilverDROID Configuration Example",
+  "_comment2": "Copy this file to app/src/main/assets/config.json and customize",
+
+  "appName": "SilverDesk Staging",
+  "appVersion": "1.0.0",
+  "targetUrl": "https://silverdesk-staging.silverlabs.uk/",
+  "showUrlBar": false,
+  "allowNavigation": true,
+
+  "vpn": {
+    "_comment": "Optional WireGuard VPN configuration",
+    "enabled": false,
+    "autoConnect": true,
+    "privateKey": "YOUR_PRIVATE_KEY_HERE",
+    "address": "10.0.0.2/24",
+    "dns": ["1.1.1.1", "1.0.0.1"],
+    "peers": [
+      {
+        "publicKey": "SERVER_PUBLIC_KEY_HERE",
+        "endpoint": "vpn.silverlabs.uk:51820",
+        "allowedIps": ["0.0.0.0/0"],
+        "persistentKeepalive": 25
+      }
+    ]
+  },
+
+  "tor": {
+    "_comment": "Optional Tor routing via Orbot",
+    "_comment2": "Requires Orbot app to be installed",
+    "enabled": false,
+    "autoConnect": false,
+    "useBridges": false,
+    "bridges": [],
+    "socksPort": 9050,
+    "controlPort": 9051
+  },
+
+  "theme": {
+    "_comment": "Optional custom theming (hex colors)",
+    "primaryColor": "#1976D2",
+    "backgroundColor": "#FFFFFF",
+    "statusBarColor": "#1976D2"
+  }
+}