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>

app/src/main/kotlin/uk/silverlabs/silverdroid/config/AppConfig.kt

@@ -0,0 +1,62 @@
+package uk.silverlabs.silverdroid.config
+
+import kotlinx.serialization.Serializable
+
+/**
+ * Application configuration that can be customized per deployment
+ */
+@Serializable
+data class AppConfig(
+    // App branding
+    val appName: String = "SilverDROID",
+    val appVersion: String = "1.0.0",
+
+    // Target URL configuration
+    val targetUrl: String,
+    val showUrlBar: Boolean = false,
+    val allowNavigation: Boolean = true,
+
+    // VPN configuration (optional)
+    val vpn: VpnConfig? = null,
+
+    // Tor configuration (optional)
+    val tor: TorConfig? = null,
+
+    // Theme customization
+    val theme: ThemeConfig = ThemeConfig()
+)
+
+@Serializable
+data class VpnConfig(
+    val enabled: Boolean = false,
+    val autoConnect: Boolean = true,
+    val privateKey: String,
+    val address: String,
+    val dns: List<String> = emptyList(),
+    val peers: List<PeerConfig>
+)
+
+@Serializable
+data class PeerConfig(
+    val publicKey: String,
+    val endpoint: String,
+    val allowedIps: List<String> = listOf("0.0.0.0/0"),
+    val persistentKeepalive: Int = 25
+)
+
+@Serializable
+data class TorConfig(
+    val enabled: Boolean = false,
+    val autoConnect: Boolean = true,
+    val useBridges: Boolean = false,
+    val bridges: List<String> = emptyList(),
+    val socksPort: Int = 9050,
+    val controlPort: Int = 9051
+)
+
+@Serializable
+data class ThemeConfig(
+    val primaryColor: String? = null,
+    val backgroundColor: String? = null,
+    val statusBarColor: String? = null
+)

app/src/main/kotlin/uk/silverlabs/silverdroid/config/ConfigLoader.kt

@@ -0,0 +1,82 @@
+package uk.silverlabs.silverdroid.config
+
+import android.content.Context
+import kotlinx.serialization.json.Json
+import java.io.IOException
+
+/**
+ * Loads app configuration from assets/config.json
+ * Falls back to default configuration if file doesn't exist
+ */
+object ConfigLoader {
+
+    private const val CONFIG_FILE = "config.json"
+
+    private val json = Json {
+        ignoreUnknownKeys = true
+        isLenient = true
+        prettyPrint = true
+    }
+
+    fun loadConfig(context: Context): AppConfig {
+        return try {
+            val configJson = context.assets.open(CONFIG_FILE).bufferedReader().use { it.readText() }
+            json.decodeFromString<AppConfig>(configJson)
+        } catch (e: IOException) {
+            // File doesn't exist, return default config
+            getDefaultConfig()
+        } catch (e: Exception) {
+            // Parsing error, log and return default
+            android.util.Log.e("ConfigLoader", "Error loading config", e)
+            getDefaultConfig()
+        }
+    }
+
+    private fun getDefaultConfig() = AppConfig(
+        appName = "SilverDROID",
+        targetUrl = "https://silverdesk-staging.silverlabs.uk/",
+        showUrlBar = false,
+        allowNavigation = true
+    )
+
+    /**
+     * Example configuration for reference
+     */
+    fun getExampleConfig() = """
+    {
+      "appName": "SilverDesk Staging",
+      "appVersion": "1.0.0",
+      "targetUrl": "https://silverdesk-staging.silverlabs.uk/",
+      "showUrlBar": false,
+      "allowNavigation": true,
+      "vpn": {
+        "enabled": true,
+        "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.example.com:51820",
+            "allowedIps": ["0.0.0.0/0"],
+            "persistentKeepalive": 25
+          }
+        ]
+      },
+      "tor": {
+        "enabled": false,
+        "autoConnect": false,
+        "useBridges": false,
+        "bridges": [],
+        "socksPort": 9050,
+        "controlPort": 9051
+      },
+      "theme": {
+        "primaryColor": "#1976D2",
+        "backgroundColor": "#FFFFFF",
+        "statusBarColor": "#1976D2"
+      }
+    }
+    """.trimIndent()
+}