Add vendor scheduled date to dispatch workflow

- Add ScheduledDate field to Dispatch model and DTO
- Save scheduled date when dispatching to vendor
- Include ScheduledDate in dispatch response projections

Api.SeaHavenIndustries/Controllers/WorkOrderController.cs

@@ -648,6 +648,7 @@ namespace Api.SeaHavenIndustries.Controllers
                     d.NTEAmount,
                     d.Description,
                     d.Status,
+                    d.ScheduledDate,
                     d.DispatchedAt,
                     d.EmailSent,
                     vendorName = d.Vendor != null ? d.Vendor.CompanyName : "",
@@ -1034,6 +1035,7 @@ namespace Api.SeaHavenIndustries.Controllers
                         NTEAmount = model.NTEAmount,
                         Description = model.Description,
                         Status = "Sent",
+                        ScheduledDate = model.ScheduledDate,
                         DispatchedAt = DateTime.UtcNow,
                         ReplyToAddress = replyTo
                     };

Api.SeaHavenIndustries/DTOs/Dispatch_DTO.cs

@@ -5,6 +5,7 @@ namespace Api.SeaHavenIndustries.DTOs
         public int WorkOrderId { get; set; }
         public List<int> VendorIds { get; set; } = new();
         public decimal? NTEAmount { get; set; }
+        public DateTime? ScheduledDate { get; set; }
         public string? Description { get; set; }
     }
 }

Data.SeaHavenIndustries/Migrations/20260417154641_AddDispatchScheduledDate.cs

@@ -0,0 +1,29 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Data.SeaHavenIndustries.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddDispatchScheduledDate : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<DateTime>(
+                name: "ScheduledDate",
+                table: "Dispatches",
+                type: "datetime2",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "ScheduledDate",
+                table: "Dispatches");
+        }
+    }
+}

Data.SeaHavenIndustries/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -671,6 +671,9 @@ namespace Data.SeaHavenIndustries.Migrations
                     b.Property<string>("ReplyToAddress")
                         .HasColumnType("nvarchar(max)");
 
+                    b.Property<DateTime?>("ScheduledDate")
+                        .HasColumnType("datetime2");
+
                     b.Property<string>("Status")
                         .HasColumnType("nvarchar(max)");
 

Data.SeaHavenIndustries/Models/Dispatch.cs

@@ -16,6 +16,7 @@ namespace Data.SeaHavenIndustries
         public decimal? NTEAmount { get; set; }
         public string? Description { get; set; }
         public string? Status { get; set; }
+        public DateTime? ScheduledDate { get; set; }
         public DateTime? DispatchedAt { get; set; }
         public bool EmailSent { get; set; }
         public string? ReplyToAddress { get; set; }