Harden cleanup and reduce internal RAM use. Phase 8C nearly validated

and somewhat stable.

src/web_server.c

@@ -695,8 +695,13 @@ esp_err_t web_server_start(void)
         serial_transport_attached = attach_error == ESP_OK;
     }
     if (error != ESP_OK && server != NULL) {
-        (void)httpd_ssl_stop(server);
-        server = NULL;
+        esp_err_t cleanup_error = httpd_ssl_stop(server);
+        if (cleanup_error == ESP_OK) {
+            server = NULL;
+        } else {
+            /* Retain ownership so stop can retry and start cannot allocate a second server. */
+            error = cleanup_error;
+        }
     }
 
     xSemaphoreTake(s_server_mutex, portMAX_DELAY);
@@ -708,6 +713,8 @@ esp_err_t web_server_start(void)
         s_server = server;
         ++s_counters.starts;
     } else {
+        /* A non-NULL handle is a partially started server whose cleanup failed. */
+        s_server = server;
         ++s_counters.start_failures;
     }
     xSemaphoreGive(s_server_mutex);