Merge pull request #199 from Sea-Haven-Industries/fix/ab/sh411-technician-assignment-backend-thr_9fpik7tdmw

Persist explicit work-order technician assignment

Data.SeaHavenIndustries/Migrations/20260929210000_SH411WorkOrderTechnicianAssigned.cs

@@ -0,0 +1,29 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Data.SeaHavenIndustries.Migrations
+{
+    [DbContext(typeof(ApplicationDbContext))]
+    [Migration("20260929210000_SH411WorkOrderTechnicianAssigned")]
+    public partial class SH411WorkOrderTechnicianAssigned : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "TechnicianAssigned",
+                table: "workOrders",
+                type: "bit",
+                nullable: true);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "TechnicianAssigned",
+                table: "workOrders");
+        }
+    }
+}

Data.SeaHavenIndustries/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -2826,6 +2826,9 @@ namespace Data.SeaHavenIndustries.Migrations
                     b.Property<string>("FrozenCompany")
                         .HasColumnType("nvarchar(max)");
 
+                    b.Property<bool?>("TechnicianAssigned")
+                        .HasColumnType("bit");
+
                     b.Property<string>("FrozenPoc")
                         .HasColumnType("nvarchar(max)");
 

Data.SeaHavenIndustries/Models/WorkOrderCompletionSnapshot.cs

@@ -17,6 +17,7 @@ namespace Data.SeaHavenIndustries
     {
         public string? Name { get; set; }
         public string? ContactName { get; set; }
+        public bool? TechnicianAssigned { get; set; }
         public string? Address { get; set; }
         public string? City { get; set; }
         public string? State { get; set; }

Data.SeaHavenIndustries/Models/WorkerOrder.cs

@@ -51,6 +51,8 @@ namespace Data.SeaHavenIndustries
         public int? PrimaryDispatchId { get; set; }
         [ForeignKey(nameof(PrimaryDispatchId))]
         public virtual Dispatch? PrimaryDispatch { get; set; }
+        /// <summary>Explicit technician selection for this work order; null preserves legacy vendor-contact behavior.</summary>
+        public bool? TechnicianAssigned { get; set; }
 
         // --- Service & Notes / POC (structured create) ---
         [MaxLength(200)]

SeaHaven.DataServices/Helpers/WorkOrderBoardProjection.cs

@@ -89,6 +89,7 @@ namespace SeaHaven.DataServices.Helpers
                     TechName = w.PrimaryDispatch != null && w.PrimaryDispatch.Vendor != null
                         ? w.PrimaryDispatch.Vendor.ContactName
                         : null,
+                    w.TechnicianAssigned,
                     DispatchTechPhone = w.PrimaryDispatch != null ? w.PrimaryDispatch.TechPhone : null,
                     WoTechPhone = w.TechPhone,
                     VendorPhone = w.PrimaryDispatch != null && w.PrimaryDispatch.Vendor != null
@@ -129,6 +130,7 @@ namespace SeaHaven.DataServices.Helpers
                 var frozenPoc = w.LifecycleStatus == LifecycleStatus.Completed
                     ? Deserialize<WorkOrderFrozenPoc>(w.FrozenPoc)
                     : null;
+                var technicianAssigned = frozenCompany?.TechnicianAssigned ?? w.TechnicianAssigned;
                 var primaryFrozenPoc = frozenPoc?.Contacts.FirstOrDefault();
                 var pocName = primaryFrozenPoc?.Name
                     ?? FirstNotBlank(w.WoPocName, w.ContactPoc?.Name, w.SitePoc?.Name);
@@ -175,8 +177,8 @@ namespace SeaHaven.DataServices.Helpers
                     w.ScheduleWeekOnly,
                     vendorId,
                     vendorName,
-                    frozenCompany?.ContactName ?? w.TechName,
-                    frozenCompany?.Phone ?? techPhone,
+                    technicianAssigned == false ? null : frozenCompany?.ContactName ?? w.TechName,
+                    technicianAssigned == false ? null : frozenCompany?.Phone ?? techPhone,
                     w.DispatchApptDate,
                     w.Trade ?? w.Problem,
                     w.Problem,
@@ -205,7 +207,8 @@ namespace SeaHaven.DataServices.Helpers
                     frozenCompany,
                     frozenPoc,
                     w.WoPocName,
-                    w.WoPocPhone);
+                    w.WoPocPhone,
+                    technicianAssigned);
             }).ToList();
         }
 

SeaHaven.DataServices/Helpers/WorkOrderBoardSearchFilter.cs

@@ -49,7 +49,7 @@ namespace SeaHaven.DataServices.Helpers
                 || (w.Trade ?? "").ToLower().Contains(s)
                 || (w.Problem ?? "").ToLower().Contains(s)
                 || (w.PrimaryDispatch != null && w.PrimaryDispatch.Vendor != null && (w.PrimaryDispatch.Vendor.CompanyName ?? "").ToLower().Contains(s))
-                || (w.PrimaryDispatch != null && w.PrimaryDispatch.Vendor != null && (w.PrimaryDispatch.Vendor.ContactName ?? "").ToLower().Contains(s))
+                || (w.TechnicianAssigned != false && w.PrimaryDispatch != null && w.PrimaryDispatch.Vendor != null && (w.PrimaryDispatch.Vendor.ContactName ?? "").ToLower().Contains(s))
                 || (w.Status ?? "").ToLower().Contains(s)
                 || (w.WorkOrderType == WorkOrderType.PO && "po".Contains(s))
                 || (w.WorkOrderType == WorkOrderType.PM && "pm".Contains(s))

SeaHaven.DataServices/Interfaces/WorkOrderBoardModels.cs

@@ -73,7 +73,8 @@ namespace SeaHaven.DataServices.Interfaces
         WorkOrderFrozenCompany? FrozenCompany = null,
         WorkOrderFrozenPoc? FrozenPoc = null,
         string? WoPocName = null,
-        string? WoPocPhone = null);
+        string? WoPocPhone = null,
+        bool? TechnicianAssigned = null);
 
     public record WorkOrderBoardQueryResult(
         IReadOnlyList<WorkOrderBoardRawRow> ScheduledRows,

SeaHaven.Services/DTOs/WorkOrderBoardDTOs.cs

@@ -51,6 +51,7 @@ namespace SeaHaven.Services.DTOs
     {
         public string? Name { get; set; }
         public string? ContactName { get; set; }
+        public bool? TechnicianAssigned { get; set; }
         public string? Address { get; set; }
         public string? City { get; set; }
         public string? State { get; set; }
@@ -112,6 +113,7 @@ namespace SeaHaven.Services.DTOs
         public string? DayGroup { get; set; }
         public int? VendorId { get; set; }
         public string? VendorName { get; set; }
+        public bool? TechnicianAssigned { get; set; }
         /// <summary>
         /// Primary dispatch status. Inactive statuses are not a live company assignment.
         /// </summary>
@@ -147,6 +149,8 @@ namespace SeaHaven.Services.DTOs
     {
         public string Field { get; set; } = "";
         public string? Value { get; set; }
+        /// <summary>Explicit technician-selection state, accepted only with a vendorId patch.</summary>
+        public bool? TechnicianAssigned { get; set; }
         public string? WorkOrderVersion { get; set; }
         public string? DispatchVersion { get; set; }
         public int? PrimaryDispatchId { get; set; }

SeaHaven.Services/DTOs/WorkOrderBoardRequestDTOs.cs

@@ -45,6 +45,8 @@ namespace SeaHaven.Services.DTOs
         /// <summary>Optional create-time lifecycle. When omitted, server defaults to Incomplete.</summary>
         public LifecycleStatus? LifecycleStatus { get; set; }
         public int? VendorId { get; set; }
+        /// <summary>Optional explicit technician-selection state for the selected vendor.</summary>
+        public bool? TechnicianAssigned { get; set; }
         public DateTime? ApptDate { get; set; }
         public string? ApptTime { get; set; }
         public int? PocContactId { get; set; }

SeaHaven.Services/Helpers/WorkOrderCompletionSnapshotMapper.cs

@@ -57,7 +57,8 @@ namespace SeaHaven.Services.Helpers
                     new WorkOrderFrozenCompany
                     {
                         Name = liveVendor.CompanyName,
-                        ContactName = liveVendor.ContactName,
+                        ContactName = workOrder.TechnicianAssigned == false ? null : liveVendor.ContactName,
+                        TechnicianAssigned = workOrder.TechnicianAssigned,
                         Address = liveVendor.Address,
                         City = liveVendor.City,
                         State = liveVendor.State,

SeaHaven.Services/Implementation/WorkOrderBoardCreateService.cs

@@ -94,6 +94,12 @@ namespace SeaHaven.Services.Implementation
                 || request.ApptDate.HasValue
                 || !string.IsNullOrWhiteSpace(request.ApptTime);
 
+            if (request.TechnicianAssigned.HasValue
+                && (!request.VendorId.HasValue || request.VendorId.Value <= 0))
+                throw new WorkOrderBoardValidationException(
+                    "DispatchRequired",
+                    "technicianAssigned requires a positive vendorId.");
+
             if (request.VendorId.HasValue && request.VendorId.Value > 0)
             {
                 if (!await _mutationData.VendorExistsAsync(request.VendorId.Value, cancellationToken))
@@ -128,6 +134,7 @@ namespace SeaHaven.Services.Implementation
                 TargetWeek = request.TargetWeek,
                 ScheduleWeekOnly = request.ScheduleWeekOnly,
                 DocStatus = request.DocStatus,
+                TechnicianAssigned = request.TechnicianAssigned,
                 createdby = actorId,
                 CreatedDate = DateTime.UtcNow,
                 istemplate = false
@@ -159,6 +166,12 @@ namespace SeaHaven.Services.Implementation
                 WorkOrderBoardFieldMutations.BoardFieldChange.Changed("LifecycleStatus", "", workOrder.LifecycleStatus?.ToString() ?? LifecycleStatus.Incomplete.ToString())
             };
 
+            if (request.TechnicianAssigned.HasValue)
+                changes.Add(WorkOrderBoardFieldMutations.BoardFieldChange.Changed(
+                    "TechnicianAssigned",
+                    "",
+                    request.TechnicianAssigned.Value.ToString()));
+
             if (workOrder.Severity != null)
                 changes.Add(WorkOrderBoardFieldMutations.BoardFieldChange.Changed("Severity", "", workOrder.Severity));
 
@@ -417,7 +430,9 @@ namespace SeaHaven.Services.Implementation
         {
             foreach (var change in changes.Where(c => c.HasChanged))
             {
-                var dispatchId = change.DispatchId ?? (dispatch?.Id > 0 ? dispatch.Id : null);
+                var dispatchId = change.FieldName == "TechnicianAssigned"
+                    ? null
+                    : change.DispatchId ?? (dispatch?.Id > 0 ? dispatch.Id : null);
                 switch (change.Action)
                 {
                     case AuditActionType.StatusChanged:

SeaHaven.Services/Implementation/WorkOrderBoardService.cs

@@ -134,6 +134,7 @@ namespace SeaHaven.Services.Implementation
                 DayGroup = WorkOrderDerivedFields.GetDayGroup(row.ScheduledDate),
                 VendorId = vendorId,
                 VendorName = vendorName,
+                TechnicianAssigned = row.TechnicianAssigned,
                 PrimaryDispatchStatus = row.PrimaryDispatchStatus,
                 TechName = row.TechName,
                 TechPhone = row.TechPhone,
@@ -202,6 +203,7 @@ namespace SeaHaven.Services.Implementation
                 {
                     Name = company.Name,
                     ContactName = company.ContactName,
+                    TechnicianAssigned = company.TechnicianAssigned,
                     Address = company.Address,
                     City = company.City,
                     State = company.State,

SeaHaven.Services/Implementation/WorkOrderBoardUpdateService.cs

@@ -51,6 +51,18 @@ namespace SeaHaven.Services.Implementation
                 if (canonicalField == null)
                     throw new WorkOrderBoardValidationException("InvalidField", $"Field '{field}' is not editable.");
 
+                if (request.TechnicianAssigned.HasValue
+                    && !canonicalField.Equals(WorkOrderBoardFieldNames.VendorId, StringComparison.OrdinalIgnoreCase))
+                    throw new WorkOrderBoardValidationException(
+                        "InvalidField",
+                        "technicianAssigned can only be supplied with a vendorId patch.");
+
+                if (request.TechnicianAssigned.HasValue
+                    && !ParseVendorIdHint(request.Value).HasValue)
+                    throw new WorkOrderBoardValidationException(
+                        "InvalidValue",
+                        "technicianAssigned requires a positive vendorId.");
+
                 var workOrderVersion = ParseRowVersion(request.WorkOrderVersion, "workOrderVersion");
                 if (workOrderVersion == null)
                     throw new WorkOrderBoardValidationException("WorkOrderVersionRequired", "workOrderVersion is required.");
@@ -132,10 +144,30 @@ namespace SeaHaven.Services.Implementation
                         _mutationData.DetachWorkOrderFromDispatch(previousDispatch, workOrder.Id);
                 }
 
+                var priorVendorId = resolved?.Previous?.VendorId
+                    ?? (resolved is { Created: true } ? null : resolved?.Dispatch.VendorId);
                 var auditField = WorkOrderBoardFieldNames.ToAuditFieldName(canonicalField);
                 var lifecycleBefore = workOrder.LifecycleStatus;
                 var changes = await ApplyFieldMutationAsync(canonicalField, workOrder, dispatch, request.Value, auditField, ct);
 
+                if (canonicalField.Equals(WorkOrderBoardFieldNames.VendorId, StringComparison.OrdinalIgnoreCase)
+                    && resolved != null)
+                {
+                    var requestedVendorId = ParseVendorIdHint(request.Value);
+                    var vendorChanged = requestedVendorId.HasValue && priorVendorId != requestedVendorId.Value;
+                    var nextTechnicianAssigned = request.TechnicianAssigned
+                        ?? (vendorChanged ? null : workOrder.TechnicianAssigned);
+                    if (workOrder.TechnicianAssigned != nextTechnicianAssigned)
+                    {
+                        var oldValue = workOrder.TechnicianAssigned?.ToString();
+                        workOrder.TechnicianAssigned = nextTechnicianAssigned;
+                        changes.Add(FieldChange.ForField(
+                            "TechnicianAssigned",
+                            oldValue,
+                            nextTechnicianAssigned?.ToString()));
+                    }
+                }
+
                 // Cancelling the work order cancels its pending uplift in the same action: the
                 // withdrawal and its own audit entry are staged here and committed by the same
                 // save as the status change.
@@ -147,6 +179,9 @@ namespace SeaHaven.Services.Implementation
                     && canonicalField.Equals(WorkOrderBoardFieldNames.VendorId, StringComparison.OrdinalIgnoreCase))
                 {
                     var previousVendor = resolved.Previous?.VendorId.ToString() ?? "";
+                    var technicianAssignmentChanges = changes
+                        .Where(change => change.FieldName == "TechnicianAssigned")
+                        .ToList();
                     changes = new List<FieldChange>
                     {
                         FieldChange.ForField(
@@ -155,6 +190,7 @@ namespace SeaHaven.Services.Implementation
                             createdDispatch.VendorId.ToString(),
                             createdDispatch.Id)
                     };
+                    changes.AddRange(technicianAssignmentChanges);
                 }
                 else
                 {
@@ -172,7 +208,9 @@ namespace SeaHaven.Services.Implementation
 
                 foreach (var change in changes)
                 {
-                    var dispatchId = change.DispatchId ?? (dispatch?.Id > 0 ? dispatch.Id : null);
+                    var dispatchId = change.FieldName == "TechnicianAssigned"
+                        ? null
+                        : change.DispatchId ?? (dispatch?.Id > 0 ? dispatch.Id : null);
                     switch (change.Action)
                     {
                         case AuditActionType.StatusChanged:

SeaHaven.Services/Implementation/WorkOrderDetailService.cs

@@ -123,6 +123,7 @@ namespace SeaHaven.Services.Implementation
                 DayGroup = row.DayGroup,
                 VendorId = row.VendorId,
                 VendorName = row.VendorName,
+                TechnicianAssigned = row.TechnicianAssigned,
                 PrimaryDispatchStatus = row.PrimaryDispatchStatus,
                 TechName = row.TechName,
                 TechPhone = row.TechPhone,

SeaHavenIndustries.Tests/WorkOrderBoardCreateRelationalTests.cs

@@ -182,7 +182,8 @@ public class WorkOrderBoardCreateRelationalTests
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
                 LocationId = 1,
-                VendorId = 5
+                VendorId = 5,
+                TechnicianAssigned = false
             }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
         }
 
@@ -192,6 +193,10 @@ public class WorkOrderBoardCreateRelationalTests
         var dispatch = await verify.Dispatches.AsNoTracking().SingleAsync();
         Assert.Equal(result.PrimaryDispatchId, dispatch.Id);
         Assert.Equal(result.Id, dispatch.WorkOrderId);
+        Assert.False(await verify.workOrders
+            .Where(workOrder => workOrder.Id == result.Id)
+            .Select(workOrder => workOrder.TechnicianAssigned)
+            .SingleAsync());
 
         var upliftDispatch = await new UpliftDataService(verify).GetUpliftDispatchForWorkOrderAsync(
             result.Id,

SeaHavenIndustries.Tests/WorkOrderBoardUpdateServiceTests.cs

@@ -655,6 +655,185 @@ public class WorkOrderBoardUpdateServiceTests
         Assert.Equal(1, await context.Dispatches.CountAsync());
     }
 
+    [Fact]
+    public async Task PatchField_TechnicianAssignedFalseWithSameInactiveVendor_ReplacesPrimaryDispatch()
+    {
+        var (context, service) = CreateSut();
+        context.Vendors.Add(new Vendor { Id = 5, CompanyName = "Vendor Co", ContactName = "Tech One" });
+        var dispatch = new Dispatch
+        {
+            Id = 10,
+            WorkOrderId = 1,
+            VendorId = 5,
+            Status = "Refused",
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 2 }
+        };
+        var wo = new WorkOrder
+        {
+            Id = 1,
+            LifecycleStatus = LifecycleStatus.Scheduled,
+            PrimaryDispatchId = dispatch.Id,
+            TechnicianAssigned = false,
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 1 }
+        };
+        context.Dispatches.Add(dispatch);
+        context.workOrders.Add(wo);
+        await context.SaveChangesAsync();
+
+        var result = await service.PatchFieldAsync(1, new WorkOrderBoardPatchRequestDto
+        {
+            Field = WorkOrderBoardFieldNames.VendorId,
+            Value = "5",
+            TechnicianAssigned = false,
+            WorkOrderVersion = ToVersion(wo),
+            DispatchVersion = ToVersion(dispatch),
+            PrimaryDispatchId = dispatch.Id
+        }, "actor-1");
+
+        Assert.NotEqual(dispatch.Id, result.PrimaryDispatchId);
+        Assert.Equal("Pending", result.PrimaryDispatchStatus);
+        Assert.False(result.TechnicianAssigned);
+        Assert.Equal("Refused", (await context.Dispatches.SingleAsync(item => item.Id == dispatch.Id)).Status);
+    }
+
+    [Fact]
+    public async Task PatchField_OldClientVendorChange_ResetsExplicitTechnicianStateToLegacy()
+    {
+        var (context, service) = CreateSut();
+        context.Vendors.AddRange(
+            new Vendor { Id = 1, CompanyName = "Old Co" },
+            new Vendor { Id = 5, CompanyName = "New Co" });
+        var dispatch = new Dispatch
+        {
+            Id = 10,
+            WorkOrderId = 1,
+            VendorId = 1,
+            Status = "Sent",
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 2 }
+        };
+        var wo = new WorkOrder
+        {
+            Id = 1,
+            LifecycleStatus = LifecycleStatus.Scheduled,
+            PrimaryDispatchId = dispatch.Id,
+            TechnicianAssigned = false,
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 1 }
+        };
+        context.Dispatches.Add(dispatch);
+        context.workOrders.Add(wo);
+        await context.SaveChangesAsync();
+
+        var result = await service.PatchFieldAsync(1, new WorkOrderBoardPatchRequestDto
+        {
+            Field = WorkOrderBoardFieldNames.VendorId,
+            Value = "5",
+            WorkOrderVersion = ToVersion(wo),
+            DispatchVersion = ToVersion(dispatch),
+            PrimaryDispatchId = dispatch.Id
+        }, "actor-1");
+
+        Assert.Null(result.TechnicianAssigned);
+        Assert.Equal("New Co", result.VendorName);
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(null)]
+    public async Task PatchField_OldClientSameVendor_PreservesExplicitOrLegacyState(bool? technicianAssigned)
+    {
+        var (context, service) = CreateSut();
+        context.Vendors.Add(new Vendor { Id = 5, CompanyName = "Vendor Co", ContactName = "Tech One" });
+        var dispatch = new Dispatch
+        {
+            Id = 10,
+            WorkOrderId = 1,
+            VendorId = 5,
+            Status = "Sent",
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 2 }
+        };
+        var wo = new WorkOrder
+        {
+            Id = 1,
+            LifecycleStatus = LifecycleStatus.Scheduled,
+            PrimaryDispatchId = dispatch.Id,
+            TechnicianAssigned = technicianAssigned,
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 1 }
+        };
+        context.Dispatches.Add(dispatch);
+        context.workOrders.Add(wo);
+        await context.SaveChangesAsync();
+
+        var result = await service.PatchFieldAsync(1, new WorkOrderBoardPatchRequestDto
+        {
+            Field = WorkOrderBoardFieldNames.VendorId,
+            Value = "5",
+            WorkOrderVersion = ToVersion(wo),
+            DispatchVersion = ToVersion(dispatch),
+            PrimaryDispatchId = dispatch.Id
+        }, "actor-1");
+
+        Assert.Equal(technicianAssigned, result.TechnicianAssigned);
+        Assert.Equal("Tech One", result.TechName);
+        Assert.Equal(dispatch.Id, result.PrimaryDispatchId);
+    }
+
+    [Fact]
+    public async Task PatchField_NewVendorWithExplicitNoTechnician_AuditsWorkOrderState()
+    {
+        var (context, service) = CreateSut();
+        context.Vendors.Add(new Vendor { Id = 5, CompanyName = "Vendor Co" });
+        var wo = new WorkOrder
+        {
+            Id = 1,
+            LifecycleStatus = LifecycleStatus.Incomplete,
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 1 }
+        };
+        context.workOrders.Add(wo);
+        await context.SaveChangesAsync();
+
+        var result = await service.PatchFieldAsync(1, new WorkOrderBoardPatchRequestDto
+        {
+            Field = WorkOrderBoardFieldNames.VendorId,
+            Value = "5",
+            TechnicianAssigned = false,
+            WorkOrderVersion = ToVersion(wo)
+        }, "actor-1");
+
+        Assert.False(result.TechnicianAssigned);
+        var audit = await context.WorkOrderAuditLogs.SingleAsync(item => item.FieldName == "TechnicianAssigned");
+        Assert.Equal(AuditActionType.FieldChanged.ToString(), audit.Action);
+        Assert.Equal("False", audit.NewValue);
+        Assert.Null(audit.DispatchId);
+    }
+
+    [Fact]
+    public async Task PatchField_TechnicianAssignedOnAnotherField_IsRejectedWithoutMutation()
+    {
+        var (context, service) = CreateSut();
+        var wo = new WorkOrder
+        {
+            Id = 1,
+            LifecycleStatus = LifecycleStatus.Incomplete,
+            TechnicianAssigned = true,
+            RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 1 }
+        };
+        context.workOrders.Add(wo);
+        await context.SaveChangesAsync();
+
+        var exception = await Assert.ThrowsAsync<WorkOrderBoardValidationException>(() =>
+            service.PatchFieldAsync(1, new WorkOrderBoardPatchRequestDto
+            {
+                Field = WorkOrderBoardFieldNames.ScheduledDate,
+                Value = "2026-09-30",
+                TechnicianAssigned = false,
+                WorkOrderVersion = ToVersion(wo)
+            }, "actor-1"));
+
+        Assert.Equal("InvalidField", exception.Code);
+        Assert.True((await context.workOrders.SingleAsync()).TechnicianAssigned);
+        Assert.Empty(await context.WorkOrderAuditLogs.ToListAsync());
+    }
+
     [Theory]
     [InlineData("Cancelled")]
     [InlineData("Canceled")]

SeaHavenIndustries.Tests/WorkOrderCompletionFreezeTests.cs

@@ -149,6 +149,57 @@ public class WorkOrderCompletionFreezeTests
         Assert.Null(persisted.FrozenCompany);
     }
 
+    [Fact]
+    public async Task CompletionWithExplicitNoTechnicianFreezesCompanyWithoutTechnicianContact()
+    {
+        await using var context = CreateContext();
+        var service = CreateService(context);
+        var vendor = new Vendor
+        {
+            Id = 20,
+            CompanyName = "Frozen Vendor",
+            ContactName = "Do Not Freeze Tech",
+            CompanyPhone = "312-555-0200",
+            Email = "company@example.com"
+        };
+        var dispatch = new Dispatch
+        {
+            Id = 40,
+            WorkOrderId = 1,
+            VendorId = vendor.Id,
+            Vendor = vendor,
+            Status = "Sent",
+            TechPhone = "312-555-0299"
+        };
+        var workOrder = new WorkOrder
+        {
+            Id = 1,
+            LifecycleStatus = LifecycleStatus.Scheduled,
+            ScheduledDate = DateTime.UtcNow.Date.AddDays(1),
+            PrimaryDispatchId = dispatch.Id,
+            PrimaryDispatch = dispatch,
+            TechnicianAssigned = false,
+            RowVersion = Version()
+        };
+        context.AddRange(vendor, dispatch, workOrder);
+        await context.SaveChangesAsync();
+
+        var completed = await service.PatchFieldAsync(
+            workOrder.Id,
+            Patch(WorkOrderBoardFieldNames.LifecycleStatus, "Complete", workOrder),
+            "actor-1");
+        var persisted = await context.workOrders.SingleAsync();
+        var frozen = WorkOrderCompletionSnapshotMapper.ParseCompany(persisted.FrozenCompany);
+
+        Assert.False(completed.TechnicianAssigned);
+        Assert.Null(completed.TechName);
+        Assert.Null(completed.TechPhone);
+        Assert.False(frozen?.TechnicianAssigned);
+        Assert.Null(frozen?.ContactName);
+        Assert.Equal("312-555-0200", frozen?.Phone);
+        Assert.Equal("company@example.com", frozen?.Email);
+    }
+
     [Fact]
     public async Task OpenWorkOrderProjectionKeepsUsingLiveLocation()
     {

SeaHavenIndustries.Tests/WorkOrderMigrationDiscoveryTests.cs

@@ -45,4 +45,17 @@ public class WorkOrderMigrationDiscoveryTests
 
         Assert.Contains("20260826120000_SH221_LocationAccountScope", migrations);
     }
+
+    [Fact]
+    public void SH411_TechnicianAssigned_is_discoverable_by_ef_runtime()
+    {
+        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
+            .UseSqlite("DataSource=:memory:")
+            .Options;
+
+        using var context = new ApplicationDbContext(options);
+        var migrations = context.Database.GetMigrations().ToList();
+
+        Assert.Contains("20260929210000_SH411WorkOrderTechnicianAssigned", migrations);
+    }
 }

SeaHavenIndustries.Tests/WorkOrderTechnicianAssignmentRelationalTests.cs

@@ -0,0 +1,216 @@
+using Data.SeaHavenIndustries;
+using Data.SeaHavenIndustries.Enums;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Helpers;
+using SeaHaven.DataServices.Implementation;
+using SeaHaven.Services.DTOs;
+using SeaHaven.Services.Helpers;
+using SeaHaven.Services.Implementation;
+
+namespace SeaHavenIndustries.Tests;
+
+public class WorkOrderTechnicianAssignmentRelationalTests
+{
+    [Fact]
+    public async Task ClearingTechnicianOnOneWorkOrder_PreservesSharedDispatchAndSiblingSelectionAfterReload()
+    {
+        await using var connection = new SqliteConnection("Data Source=:memory:;Foreign Keys=True");
+        await connection.OpenAsync();
+        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
+            .UseSqlite(connection)
+            .Options;
+
+        byte[] workOrderVersion = { 1, 0, 0, 0, 0, 0, 0, 1 };
+        byte[] dispatchVersion = { 1, 0, 0, 0, 0, 0, 0, 2 };
+        await using (var seed = new SqliteBoardTestDbContext(options))
+        {
+            await seed.Database.EnsureCreatedAsync();
+            await WorkOrderAccountTestHelpers.EnsureAccountAsync(seed);
+            seed.Users.Add(new ApplicationUser
+            {
+                Id = "actor-1",
+                UserName = "actor-1",
+                NormalizedUserName = "ACTOR-1",
+                Email = "actor@test.local",
+                NormalizedEmail = "ACTOR@TEST.LOCAL"
+            });
+            seed.Vendors.Add(new Vendor
+            {
+                Id = 5,
+                CompanyName = "Acme HVAC",
+                ContactName = "Technician One",
+                CompanyPhone = "312-555-0100"
+            });
+            await seed.SaveChangesAsync();
+
+            var dispatch = new Dispatch
+            {
+                Id = 10,
+                VendorId = 5,
+                Status = "Sent",
+                TechPhone = "312-555-0199",
+                RowVersion = dispatchVersion
+            };
+            seed.Dispatches.Add(dispatch);
+            seed.workOrders.AddRange(
+                new WorkOrder
+                {
+                    Id = 1,
+                    AccountId = 1,
+                    LifecycleStatus = LifecycleStatus.Scheduled,
+                    ScheduledDate = new DateTime(2026, 9, 30),
+                    PrimaryDispatchId = 10,
+                    TechnicianAssigned = true,
+                    RowVersion = workOrderVersion
+                },
+                new WorkOrder
+                {
+                    Id = 2,
+                    AccountId = 1,
+                    LifecycleStatus = LifecycleStatus.Scheduled,
+                    ScheduledDate = new DateTime(2026, 9, 30),
+                    PrimaryDispatchId = 10,
+                    RowVersion = new byte[] { 2, 0, 0, 0, 0, 0, 0, 1 }
+                });
+            await seed.SaveChangesAsync();
+
+            dispatch.WorkOrderId = 1;
+            seed.DispatchWorkOrders.Add(new DispatchWorkOrder { Id = 20, DispatchId = 10, WorkOrderId = 2 });
+            await seed.SaveChangesAsync();
+        }
+
+        await using (var context = new SqliteBoardTestDbContext(options))
+        {
+            var fieldLocks = new WorkOrderFieldLockService(new WorkOrderFieldLockDataService(context));
+            var audit = new WorkOrderAuditService(new WorkOrderAuditDataService(context), fieldLocks);
+            var service = WorkOrderAccountTestHelpers.BoardUpdateService(context, audit);
+            var updated = await service.PatchFieldAsync(1, new WorkOrderBoardPatchRequestDto
+            {
+                Field = WorkOrderBoardFieldNames.VendorId,
+                Value = "5",
+                TechnicianAssigned = false,
+                WorkOrderVersion = Convert.ToBase64String(workOrderVersion),
+                DispatchVersion = Convert.ToBase64String(dispatchVersion),
+                PrimaryDispatchId = 10
+            }, "actor-1");
+
+            Assert.False(updated.TechnicianAssigned);
+            Assert.Equal(10, updated.PrimaryDispatchId);
+        }
+
+        await using var verify = new SqliteBoardTestDbContext(options);
+        var data = new WorkOrderBoardDataService(verify);
+        var workOrderA = Assert.IsType<SeaHaven.DataServices.Interfaces.WorkOrderBoardRawRow>(
+            await data.GetBoardRowByIdAsync(1));
+        var workOrderB = Assert.IsType<SeaHaven.DataServices.Interfaces.WorkOrderBoardRawRow>(
+            await data.GetBoardRowByIdAsync(2));
+
+        Assert.False(workOrderA.TechnicianAssigned);
+        Assert.Null(workOrderA.TechName);
+        Assert.Null(workOrderA.TechPhone);
+        Assert.Equal("Technician One", workOrderB.TechName);
+        Assert.Equal("312-555-0199", workOrderB.TechPhone);
+        Assert.Equal(10, workOrderA.PrimaryDispatchId);
+        Assert.Equal(10, workOrderB.PrimaryDispatchId);
+        Assert.Equal(5, workOrderA.VendorId);
+        Assert.Equal(5, workOrderB.VendorId);
+    }
+
+    [Fact]
+    public async Task TechnicianNameSearch_MatchesLegacyAndAssignedRows_ButNotExplicitlyClearedRow()
+    {
+        await using var connection = new SqliteConnection("Data Source=:memory:;Foreign Keys=True");
+        await connection.OpenAsync();
+        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
+            .UseSqlite(connection)
+            .Options;
+
+        await using (var seed = new SqliteBoardTestDbContext(options))
+        {
+            await seed.Database.EnsureCreatedAsync();
+            await WorkOrderAccountTestHelpers.EnsureAccountAsync(seed);
+            seed.Vendors.Add(new Vendor
+            {
+                Id = 5,
+                CompanyName = "Acme HVAC",
+                ContactName = "Technician One",
+                CompanyPhone = "312-555-0100"
+            });
+            seed.Dispatches.AddRange(
+                new Dispatch { Id = 10, VendorId = 5, Status = "Sent", RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 2 } },
+                new Dispatch { Id = 11, VendorId = 5, Status = "Sent", RowVersion = new byte[] { 2, 0, 0, 0, 0, 0, 0, 2 } },
+                new Dispatch { Id = 12, VendorId = 5, Status = "Sent", RowVersion = new byte[] { 3, 0, 0, 0, 0, 0, 0, 2 } });
+            seed.workOrders.AddRange(
+                new WorkOrder
+                {
+                    Id = 1,
+                    AccountId = 1,
+                    LifecycleStatus = LifecycleStatus.Scheduled,
+                    PrimaryDispatchId = 10,
+                    TechnicianAssigned = null,
+                    RowVersion = new byte[] { 1, 0, 0, 0, 0, 0, 0, 1 }
+                },
+                new WorkOrder
+                {
+                    Id = 2,
+                    AccountId = 1,
+                    LifecycleStatus = LifecycleStatus.Scheduled,
+                    PrimaryDispatchId = 11,
+                    TechnicianAssigned = true,
+                    RowVersion = new byte[] { 2, 0, 0, 0, 0, 0, 0, 1 }
+                },
+                new WorkOrder
+                {
+                    Id = 3,
+                    AccountId = 1,
+                    LifecycleStatus = LifecycleStatus.Scheduled,
+                    PrimaryDispatchId = 12,
+                    TechnicianAssigned = false,
+                    RowVersion = new byte[] { 3, 0, 0, 0, 0, 0, 0, 1 }
+                });
+            await seed.SaveChangesAsync();
+        }
+
+        await using var context = new SqliteBoardTestDbContext(options);
+
+        var technicianMatches = await WorkOrderBoardSearchFilter
+            .Apply(context.workOrders.AsQueryable(), "Technician One")
+            .Select(w => w.Id)
+            .OrderBy(id => id)
+            .ToListAsync();
+        Assert.Equal(new[] { 1, 2 }, technicianMatches);
+
+        var companyMatches = await WorkOrderBoardSearchFilter
+            .Apply(context.workOrders.AsQueryable(), "Acme HVAC")
+            .Select(w => w.Id)
+            .OrderBy(id => id)
+            .ToListAsync();
+        Assert.Equal(new[] { 1, 2, 3 }, companyMatches);
+    }
+
+    private sealed class SqliteBoardTestDbContext : ApplicationDbContext
+    {
+        public SqliteBoardTestDbContext(DbContextOptions<ApplicationDbContext> options)
+            : base(options)
+        {
+        }
+
+        protected override void OnModelCreating(ModelBuilder builder)
+        {
+            base.OnModelCreating(builder);
+            foreach (var index in builder.Model.GetEntityTypes().SelectMany(entity => entity.GetIndexes()))
+            {
+                if (index.GetFilter() != null)
+                    index.SetFilter(null);
+            }
+
+            foreach (var entityType in new[] { typeof(WorkOrder), typeof(Dispatch) })
+            {
+                var property = builder.Entity(entityType).Property("RowVersion").Metadata;
+                property.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.Never;
+                property.IsConcurrencyToken = false;
+            }
+        }
+    }
+}