feat(config): add proxy section to unified config loader

- merge proxy config with defaults in loadUnifiedConfig

- preserve user overrides for remote/fallback/local sections

src/config/unified-config-loader.ts

@@ -16,6 +16,7 @@ import {
   UNIFIED_CONFIG_VERSION,
   DEFAULT_COPILOT_CONFIG,
   DEFAULT_GLOBAL_ENV,
+  DEFAULT_PROXY_CONFIG,
   GlobalEnvConfig,
 } from './unified-config-types';
 import { isUnifiedConfigEnabled } from './feature-flags';
@@ -177,6 +178,24 @@ function mergeWithDefaults(partial: Partial<UnifiedConfig>): UnifiedConfig {
       enabled: partial.global_env?.enabled ?? true,
       env: partial.global_env?.env ?? { ...DEFAULT_GLOBAL_ENV },
     },
+    // Proxy config - remote/local CLIProxyAPI settings
+    proxy: {
+      remote: {
+        enabled: partial.proxy?.remote?.enabled ?? DEFAULT_PROXY_CONFIG.remote.enabled,
+        host: partial.proxy?.remote?.host ?? DEFAULT_PROXY_CONFIG.remote.host,
+        port: partial.proxy?.remote?.port ?? DEFAULT_PROXY_CONFIG.remote.port,
+        protocol: partial.proxy?.remote?.protocol ?? DEFAULT_PROXY_CONFIG.remote.protocol,
+        auth_token: partial.proxy?.remote?.auth_token ?? DEFAULT_PROXY_CONFIG.remote.auth_token,
+      },
+      fallback: {
+        enabled: partial.proxy?.fallback?.enabled ?? DEFAULT_PROXY_CONFIG.fallback.enabled,
+        auto_start: partial.proxy?.fallback?.auto_start ?? DEFAULT_PROXY_CONFIG.fallback.auto_start,
+      },
+      local: {
+        port: partial.proxy?.local?.port ?? DEFAULT_PROXY_CONFIG.local.port,
+        auto_start: partial.proxy?.local?.auto_start ?? DEFAULT_PROXY_CONFIG.local.auto_start,
+      },
+    },
   };
 }