refactor: change default proxy configuration to System

- Update `ProxyRepositoryImpl` to return `ProxyConfig.System` as the default fallback option.
- Change the default `proxyConfig` parameter in `HttpClientFactory` from `None` to `System`.
- Initialize `ProxyManager` with `ProxyConfig.System` as the starting state.
- Update the dependency injection logic in `SharedModule` to use `ProxyConfig.System` when the configuration fetch fails or times out.

Author: rainxchzed

core/data/src/commonMain/kotlin/zed/rainxch/core/data/di/SharedModule.kt

@@ -132,7 +132,7 @@ val networkModule =
                         withTimeout(1_500L) {
                             get<ProxyRepository>().getProxyConfig().first()
                         }
-                    }.getOrDefault(ProxyConfig.None)
+                    }.getOrDefault(ProxyConfig.System)
                 }
 
             when (config) {

core/data/src/commonMain/kotlin/zed/rainxch/core/data/network/HttpClientFactory.kt

@@ -29,7 +29,7 @@ fun createGitHubHttpClient(
     rateLimitRepository: RateLimitRepository,
     authenticationState: AuthenticationState? = null,
     scope: CoroutineScope? = null,
-    proxyConfig: ProxyConfig = ProxyConfig.None,
+    proxyConfig: ProxyConfig = ProxyConfig.System,
 ): HttpClient {
     val json =
         Json {

core/data/src/commonMain/kotlin/zed/rainxch/core/data/network/ProxyManager.kt

@@ -6,7 +6,7 @@ import kotlinx.coroutines.flow.asStateFlow
 import zed.rainxch.core.domain.model.ProxyConfig
 
 object ProxyManager {
-    private val _proxyConfig = MutableStateFlow<ProxyConfig>(ProxyConfig.None)
+    private val _proxyConfig = MutableStateFlow<ProxyConfig>(ProxyConfig.System)
     val currentProxyConfig: StateFlow<ProxyConfig> = _proxyConfig.asStateFlow()
 
     fun setNoProxy() {

core/data/src/commonMain/kotlin/zed/rainxch/core/data/repository/ProxyRepositoryImpl.kt

@@ -58,7 +58,7 @@ class ProxyRepositoryImpl(
                 }
 
                 else -> {
-                    ProxyConfig.None
+                    ProxyConfig.System
                 }
             }
         }