feat(work-orders): add file storage OpenRead port

Api.SeaHavenIndustries/Infrastructure/PortAdapters.cs

@@ -70,6 +70,33 @@ namespace Api.SeaHavenIndustries.Infrastructure
             }
         }
 
+        public Stream? OpenRead(string fileUrl)
+        {
+            if (string.IsNullOrWhiteSpace(fileUrl))
+                return null;
+
+            try
+            {
+                if (!Uri.TryCreate(fileUrl, UriKind.Absolute, out var uri))
+                    return null;
+
+                var relativePath = uri.AbsolutePath.TrimStart('/');
+                if (string.IsNullOrWhiteSpace(relativePath)
+                    || relativePath.Contains("..", StringComparison.Ordinal)
+                    || !relativePath.StartsWith("Assets/Documents/", StringComparison.OrdinalIgnoreCase))
+                {
+                    return null;
+                }
+
+                var fullPath = Path.Combine(ResolveWebRoot(), relativePath.Replace('/', Path.DirectorySeparatorChar));
+                return System.IO.File.Exists(fullPath) ? System.IO.File.OpenRead(fullPath) : null;
+            }
+            catch
+            {
+                return null;
+            }
+        }
+
         private string ResolveWebRoot()
             => _webHostEnvironment.WebRootPath
                 ?? Path.Combine(_webHostEnvironment.ContentRootPath, "wwwroot");

SeaHaven.Services/Interfaces/IServicePorts.cs

@@ -24,6 +24,12 @@ namespace SeaHaven.Services.Interfaces
         /// cannot be resolved or removed; never throws for missing paths.
         /// </summary>
         bool TryDelete(string fileUrl);
+
+        /// <summary>
+        /// Opens a previously saved file URL for reading. Returns null when the URL or file
+        /// cannot be safely resolved.
+        /// </summary>
+        Stream? OpenRead(string fileUrl);
     }
 
     /// <summary>