tun_enabled config + socks/http stress test (50 reqs, 2 workers)

- config_parser: tun_enabled в [global] (по умолчанию yes), не дефолтить
  tun_ifname если TUN не нужен
- utun_instance: уважать tun_enabled, чистые дефолты tcp_proxy TUN
- socks_proxy: фикс дэдлока — reply сразу после CONNECT, без ожидания DATA
- utun.conf.sample: документирован tun_enabled, tun_ifname
- test_socks_http_proxy: 50 запросов (SOCKS+HTTP), 2 воркера параллельно,
  файлы 1k..100k, сверка через cmp, python http.server + curl

src/config_parser.c

@@ -357,6 +357,10 @@ static int parse_global(const char *key, const char *value, struct global_config
         global->my_node_id = strtoull(value, NULL, 16);
         return 0;
     }
+    if (strcmp(key, "tun_enabled") == 0) {
+        global->tun_enabled = strcasecmp(value, "yes") == 0 || strcasecmp(value, "1") == 0 || strcasecmp(value, "true") == 0;
+        return 0;
+    }
     if (strcmp(key, "tun_ifname") == 0) {
         snprintf(global->tun_ifname, sizeof(global->tun_ifname), "%s", value);
         return 0;
@@ -937,10 +941,18 @@ static struct utun_config* parse_config_internal(FILE *fp, const char *filename)
         cfg->clients = cur_client;
     }
     
-    // Set default TUN interface name if not provided
-    if (cfg->global.tun_ifname[0] == '\0') {
-        snprintf(cfg->global.tun_ifname, sizeof(cfg->global.tun_ifname), "tun0");
-        DEBUG_INFO(DEBUG_CATEGORY_CONFIG, "Auto-generated TUN interface name: %s", cfg->global.tun_ifname);
+    // Post-parse defaults: tun_enabled=1 if not explicitly disabled
+    if (!cfg->global.tun_enabled && cfg->global.tun_ifname[0] == '\0' && cfg->global.tun_ip.family == AF_UNSPEC) {
+        // No TUN config at all — treat as explicitly off (for non-root SOCKS/HTTP-only mode)
+    } else if (!cfg->global.tun_enabled) {
+        // TUN was explicitly disabled via tun_enabled=no
+    } else {
+        // TUN enabled (default) — set default ifname if not provided
+        cfg->global.tun_enabled = 1;
+        if (cfg->global.tun_ifname[0] == '\0') {
+            snprintf(cfg->global.tun_ifname, sizeof(cfg->global.tun_ifname), "tun0");
+            DEBUG_INFO(DEBUG_CATEGORY_CONFIG, "Auto-generated TUN interface name: %s", cfg->global.tun_ifname);
+        }
     }
     
     return cfg;