feat(adminui): F15.2 batch 1 — Namespace + DriverInstance live-edit CRUD

Pattern proof for the live-edit forms gated by Phases A–D's read views.
Each entity gets a single edit page handling both create (route param
omitted) and update (route param present) modes, with RowVersion-based
optimistic concurrency checked against EF Core's
DbUpdateConcurrencyException.

Pattern:
- @page "/clusters/{id}/<thing>/new"
- @page "/clusters/{id}/<thing>/{rowId}"
- IsNew computed from rowId presence
- EditForm + DataAnnotations validation
- byte[] RowVersion stashed on FormModel; assigned to
  Entry(e).Property(e => e.RowVersion).OriginalValue before SaveChanges
- Delete button (edit mode only) flows through the same RowVersion check
- Concurrency conflict surfaces as an inline error panel; user reloads

This batch:
- NamespaceEdit.razor          — small entity, validates the pattern
- DriverEdit.razor             — keystone for everything downstream
                                 (Equipment/Tag/VirtualTag/ScriptedAlarm),
                                 JSON config editor per Q1 with reformat
                                 on save and validation pre-flight
- ClusterNamespaces row gains an Edit button + New action
- ClusterDrivers expanded view gains an Edit button + New action

Equipment/UnsArea/UnsLine/Tag/ACL/VirtualTag/ScriptedAlarm/Script forms
follow this same template in subsequent F15.2 batches.

All 9 integration tests still green; no v2 test regressions.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/ClusterDrivers.razor

@@ -8,6 +8,7 @@
 
 <div class="d-flex justify-content-between align-items-center mb-3">
     <h4 class="mb-0">Drivers &middot; <span class="mono">@ClusterId</span></h4>
+    <a href="/clusters/@ClusterId/drivers/new" class="btn btn-primary btn-sm">New driver</a>
 </div>
 
 <ClusterNav ClusterId="@ClusterId" ActiveTab="drivers" />
@@ -43,6 +44,9 @@ else
                         <span class="text-muted small ms-2">ns=@d.NamespaceId</span>
                     </summary>
                     <div style="padding:0 1rem 1rem">
+                        <div class="d-flex mb-2">
+                            <a href="/clusters/@ClusterId/drivers/@d.DriverInstanceId" class="btn btn-sm btn-outline-primary">Edit</a>
+                        </div>
                         <pre class="mono small" style="background:var(--surface-2);padding:1rem;border-radius:4px;overflow:auto">@FormatJson(d.DriverConfig)</pre>
                         @if (!string.IsNullOrWhiteSpace(d.ResilienceConfig))
                         {

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/ClusterNamespaces.razor

@@ -8,6 +8,7 @@
 
 <div class="d-flex justify-content-between align-items-center mb-3">
     <h4 class="mb-0">Namespaces &middot; <span class="mono">@ClusterId</span></h4>
+    <a href="/clusters/@ClusterId/namespaces/new" class="btn btn-primary btn-sm">New namespace</a>
 </div>
 
 <ClusterNav ClusterId="@ClusterId" ActiveTab="namespaces" />
@@ -41,6 +42,7 @@ else
                             <th>URI</th>
                             <th>Status</th>
                             <th>Notes</th>
+                            <th></th>
                         </tr>
                     </thead>
                     <tbody>
@@ -55,6 +57,7 @@ else
                                     else { <span class="chip chip-idle">Disabled</span> }
                                 </td>
                                 <td class="text-muted small">@(n.Notes ?? "")</td>
+                                <td><a href="/clusters/@ClusterId/namespaces/@n.NamespaceId" class="btn btn-sm btn-outline-primary">Edit</a></td>
                             </tr>
                         }
                     </tbody>

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/DriverEdit.razor

@@ -0,0 +1,323 @@
+@page "/clusters/{ClusterId}/drivers/new"
+@page "/clusters/{ClusterId}/drivers/{DriverInstanceId}"
+@* Per Q1 of the AdminUI rebuild plan — JSON editor only, typed driver editors deferred.
+   DriverInstance is the keystone for everything downstream (Equipment, Tag, VirtualTag,
+   ScriptedAlarm all reference DriverInstanceId), so this is the second edit page after
+   Namespace. *@
+@attribute [Microsoft.AspNetCore.Authorization.Authorize]
+@rendermode RenderMode.InteractiveServer
+@using Microsoft.AspNetCore.Components.Forms
+@using Microsoft.EntityFrameworkCore
+@using System.ComponentModel.DataAnnotations
+@using ZB.MOM.WW.OtOpcUa.Configuration
+@using ZB.MOM.WW.OtOpcUa.Configuration.Entities
+@inject IDbContextFactory<OtOpcUaConfigDbContext> DbFactory
+@inject NavigationManager Nav
+
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">@(IsNew ? "New driver instance" : "Edit driver instance") &middot; <span class="mono">@ClusterId</span></h4>
+    <a href="/clusters/@ClusterId/drivers" class="btn btn-outline-secondary btn-sm">Cancel</a>
+</div>
+
+<ClusterNav ClusterId="@ClusterId" ActiveTab="drivers" />
+
+@if (!_loaded)
+{
+    <p>Loading…</p>
+}
+else if (!IsNew && _existing is null)
+{
+    <section class="panel notice rise" style="animation-delay:.02s">
+        Driver instance <span class="mono">@DriverInstanceId</span> was not found in cluster <span class="mono">@ClusterId</span>.
+    </section>
+}
+else
+{
+    <EditForm Model="_form" OnValidSubmit="SubmitAsync" FormName="driverEdit">
+        <DataAnnotationsValidator />
+        <section class="panel rise" style="animation-delay:.02s">
+            <div class="panel-head">@(IsNew ? "Identity" : $"Edit {_form.DriverInstanceId}")</div>
+            <div style="padding:1rem">
+                <div class="row">
+                    <div class="col-md-6 mb-3">
+                        <label class="form-label" for="instId">DriverInstanceId</label>
+                        <InputText id="instId" @bind-Value="_form.DriverInstanceId" disabled="@(!IsNew)"
+                                   class="form-control form-control-sm mono"
+                                   placeholder="drv-modbus-line3-01" />
+                    </div>
+                    <div class="col-md-6 mb-3">
+                        <label class="form-label" for="name">Display name</label>
+                        <InputText id="name" @bind-Value="_form.Name" class="form-control form-control-sm"
+                                   placeholder="Line 3 Modbus" />
+                    </div>
+                </div>
+                <div class="row">
+                    <div class="col-md-6 mb-3">
+                        <label class="form-label" for="dtype">Driver type</label>
+                        <InputSelect id="dtype" @bind-Value="_form.DriverType" disabled="@(!IsNew)"
+                                     class="form-select form-select-sm">
+                            <option value="ModbusTcp">ModbusTcp</option>
+                            <option value="AbCip">AbCip</option>
+                            <option value="AbLegacy">AbLegacy</option>
+                            <option value="S7">S7</option>
+                            <option value="TwinCat">TwinCat</option>
+                            <option value="Focas">Focas</option>
+                            <option value="OpcUaClient">OpcUaClient</option>
+                            <option value="Galaxy">Galaxy</option>
+                            <option value="Historian.Wonderware">Historian.Wonderware</option>
+                        </InputSelect>
+                        <div class="form-text">Cannot be changed after creation — drives the actor type that owns this instance.</div>
+                    </div>
+                    <div class="col-md-6 mb-3">
+                        <label class="form-label" for="ns">Namespace</label>
+                        <InputSelect id="ns" @bind-Value="_form.NamespaceId" class="form-select form-select-sm">
+                            @foreach (var ns in _namespaces)
+                            {
+                                <option value="@ns.NamespaceId">@ns.NamespaceId (@ns.Kind)</option>
+                            }
+                        </InputSelect>
+                    </div>
+                </div>
+                <div class="mb-3">
+                    <label class="form-label" for="enabled">Enabled</label>
+                    <div class="form-check form-switch">
+                        <InputCheckbox id="enabled" @bind-Value="_form.Enabled" class="form-check-input" />
+                        <label class="form-check-label" for="enabled">Spawn this driver in deployments</label>
+                    </div>
+                </div>
+            </div>
+        </section>
+
+        <section class="panel rise mt-3" style="animation-delay:.08s">
+            <div class="panel-head">Driver config (JSON)</div>
+            <div style="padding:1rem">
+                <InputTextArea @bind-Value="_form.DriverConfig" rows="12"
+                               class="form-control form-control-sm mono"
+                               placeholder='{ "endpoint": "10.0.0.42:502", "slaveId": 1 }' />
+                <div class="form-text">Schemaless per driver type — validated server-side at deploy time. JSON is reformatted on save.</div>
+            </div>
+        </section>
+
+        <section class="panel rise mt-3" style="animation-delay:.14s">
+            <div class="panel-head">Resilience overrides (optional)</div>
+            <div style="padding:1rem">
+                <InputTextArea @bind-Value="_form.ResilienceConfig" rows="6"
+                               class="form-control form-control-sm mono"
+                               placeholder='Leave blank to use tier defaults' />
+                <div class="form-text">Polly pipeline overrides per docs/v2/driver-stability.md — bulkhead, retry counts, breaker thresholds. Null = use the driver type's tier defaults.</div>
+            </div>
+        </section>
+
+        @if (!string.IsNullOrWhiteSpace(_error))
+        {
+            <div class="panel notice mt-3" style="border-color:var(--alert)">@_error</div>
+        }
+
+        <div class="mt-3 d-flex gap-2">
+            <button type="submit" class="btn btn-primary" disabled="@_busy">
+                @if (_busy) { <span class="spinner-border spinner-border-sm me-1"></span> }
+                @(IsNew ? "Create" : "Save changes")
+            </button>
+            <a href="/clusters/@ClusterId/drivers" class="btn btn-outline-secondary">Cancel</a>
+            @if (!IsNew)
+            {
+                <button type="button" class="btn btn-outline-danger ms-auto" @onclick="DeleteAsync" disabled="@_busy">
+                    Delete
+                </button>
+            }
+        </div>
+    </EditForm>
+}
+
+@code {
+    [Parameter] public string ClusterId { get; set; } = "";
+    [Parameter] public string? DriverInstanceId { get; set; }
+
+    private bool IsNew => string.IsNullOrEmpty(DriverInstanceId);
+
+    private FormModel _form = new();
+    private DriverInstance? _existing;
+    private List<Namespace> _namespaces = new();
+    private bool _loaded;
+    private bool _busy;
+    private string? _error;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await using var db = await DbFactory.CreateDbContextAsync();
+        _namespaces = await db.Namespaces.AsNoTracking()
+            .Where(n => n.ClusterId == ClusterId)
+            .OrderBy(n => n.NamespaceId)
+            .ToListAsync();
+
+        if (IsNew)
+        {
+            _form = new FormModel
+            {
+                DriverInstanceId = "",
+                Name = "",
+                DriverType = "ModbusTcp",
+                NamespaceId = _namespaces.FirstOrDefault()?.NamespaceId ?? "",
+                Enabled = true,
+                DriverConfig = "{}",
+            };
+        }
+        else
+        {
+            _existing = await db.DriverInstances.AsNoTracking()
+                .FirstOrDefaultAsync(d => d.ClusterId == ClusterId && d.DriverInstanceId == DriverInstanceId);
+            if (_existing is not null)
+            {
+                _form = new FormModel
+                {
+                    DriverInstanceId = _existing.DriverInstanceId,
+                    Name = _existing.Name,
+                    DriverType = _existing.DriverType,
+                    NamespaceId = _existing.NamespaceId,
+                    Enabled = _existing.Enabled,
+                    DriverConfig = _existing.DriverConfig,
+                    ResilienceConfig = _existing.ResilienceConfig,
+                    RowVersion = _existing.RowVersion,
+                };
+            }
+        }
+        _loaded = true;
+    }
+
+    private async Task SubmitAsync()
+    {
+        _busy = true;
+        _error = null;
+        try
+        {
+            var normalizedConfig = NormalizeJson(_form.DriverConfig);
+            if (normalizedConfig is null)
+            {
+                _error = "DriverConfig is not valid JSON.";
+                return;
+            }
+            var normalizedResilience = NormalizeOptionalJson(_form.ResilienceConfig);
+            if (!string.IsNullOrWhiteSpace(_form.ResilienceConfig) && normalizedResilience is null)
+            {
+                _error = "ResilienceConfig is not valid JSON. Leave blank to use defaults.";
+                return;
+            }
+
+            await using var db = await DbFactory.CreateDbContextAsync();
+            if (IsNew)
+            {
+                if (await db.DriverInstances.AnyAsync(d => d.DriverInstanceId == _form.DriverInstanceId))
+                {
+                    _error = $"Driver instance '{_form.DriverInstanceId}' already exists.";
+                    return;
+                }
+                db.DriverInstances.Add(new DriverInstance
+                {
+                    DriverInstanceId = _form.DriverInstanceId,
+                    ClusterId = ClusterId,
+                    NamespaceId = _form.NamespaceId,
+                    Name = _form.Name,
+                    DriverType = _form.DriverType,
+                    Enabled = _form.Enabled,
+                    DriverConfig = normalizedConfig,
+                    ResilienceConfig = normalizedResilience,
+                });
+            }
+            else
+            {
+                var entity = await db.DriverInstances.FirstOrDefaultAsync(
+                    d => d.ClusterId == ClusterId && d.DriverInstanceId == DriverInstanceId);
+                if (entity is null)
+                {
+                    _error = "Row no longer exists.";
+                    return;
+                }
+                db.Entry(entity).Property(e => e.RowVersion).OriginalValue = _form.RowVersion;
+                entity.NamespaceId = _form.NamespaceId;
+                entity.Name = _form.Name;
+                entity.Enabled = _form.Enabled;
+                entity.DriverConfig = normalizedConfig;
+                entity.ResilienceConfig = normalizedResilience;
+            }
+            await db.SaveChangesAsync();
+            Nav.NavigateTo($"/clusters/{ClusterId}/drivers");
+        }
+        catch (DbUpdateConcurrencyException)
+        {
+            _error = "Another user changed this driver instance while you were editing. Reload to see the latest values, then re-apply your changes.";
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+        finally
+        {
+            _busy = false;
+        }
+    }
+
+    private async Task DeleteAsync()
+    {
+        if (IsNew) return;
+        _busy = true;
+        _error = null;
+        try
+        {
+            await using var db = await DbFactory.CreateDbContextAsync();
+            var entity = await db.DriverInstances.FirstOrDefaultAsync(
+                d => d.ClusterId == ClusterId && d.DriverInstanceId == DriverInstanceId);
+            if (entity is null)
+            {
+                Nav.NavigateTo($"/clusters/{ClusterId}/drivers");
+                return;
+            }
+            db.Entry(entity).Property(e => e.RowVersion).OriginalValue = _form.RowVersion;
+            db.DriverInstances.Remove(entity);
+            await db.SaveChangesAsync();
+            Nav.NavigateTo($"/clusters/{ClusterId}/drivers");
+        }
+        catch (DbUpdateConcurrencyException)
+        {
+            _error = "Another user changed this driver instance while you were viewing it. Reload before deleting.";
+        }
+        catch (Exception ex)
+        {
+            _error = $"Delete failed: {ex.Message}. (Likely because equipment/tags still reference this driver — remove them first.)";
+        }
+        finally
+        {
+            _busy = false;
+        }
+    }
+
+    private static string? NormalizeJson(string? input)
+    {
+        if (string.IsNullOrWhiteSpace(input)) return null;
+        try
+        {
+            using var doc = System.Text.Json.JsonDocument.Parse(input);
+            return System.Text.Json.JsonSerializer.Serialize(doc.RootElement);
+        }
+        catch { return null; }
+    }
+
+    private static string? NormalizeOptionalJson(string? input) =>
+        string.IsNullOrWhiteSpace(input) ? null : NormalizeJson(input);
+
+    private sealed class FormModel
+    {
+        [Required, RegularExpression("^[A-Za-z0-9_-]+$", ErrorMessage = "Use letters, digits, dash, underscore.")]
+        public string DriverInstanceId { get; set; } = "";
+        [Required]
+        public string Name { get; set; } = "";
+        [Required]
+        public string DriverType { get; set; } = "ModbusTcp";
+        [Required]
+        public string NamespaceId { get; set; } = "";
+        public bool Enabled { get; set; } = true;
+        [Required]
+        public string DriverConfig { get; set; } = "{}";
+        public string? ResilienceConfig { get; set; }
+        public byte[] RowVersion { get; set; } = [];
+    }
+}

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/NamespaceEdit.razor

@@ -0,0 +1,244 @@
+@page "/clusters/{ClusterId}/namespaces/new"
+@page "/clusters/{ClusterId}/namespaces/{NamespaceId}"
+@* Live-edit form pattern — one page handles both create (NamespaceId is null) and update.
+   RowVersion is preserved across post-back so EF Core enforces last-write-wins; concurrency
+   conflicts surface as a toast and reload the current row. *@
+@attribute [Microsoft.AspNetCore.Authorization.Authorize]
+@rendermode RenderMode.InteractiveServer
+@using Microsoft.AspNetCore.Components.Forms
+@using Microsoft.EntityFrameworkCore
+@using System.ComponentModel.DataAnnotations
+@using ZB.MOM.WW.OtOpcUa.Configuration
+@using ZB.MOM.WW.OtOpcUa.Configuration.Entities
+@using ZB.MOM.WW.OtOpcUa.Configuration.Enums
+@inject IDbContextFactory<OtOpcUaConfigDbContext> DbFactory
+@inject NavigationManager Nav
+
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">@(IsNew ? "New namespace" : "Edit namespace") &middot; <span class="mono">@ClusterId</span></h4>
+    <a href="/clusters/@ClusterId/namespaces" class="btn btn-outline-secondary btn-sm">Cancel</a>
+</div>
+
+<ClusterNav ClusterId="@ClusterId" ActiveTab="namespaces" />
+
+@if (!_loaded)
+{
+    <p>Loading…</p>
+}
+else if (!IsNew && _existing is null)
+{
+    <section class="panel notice rise" style="animation-delay:.02s">
+        Namespace <span class="mono">@NamespaceId</span> was not found in cluster <span class="mono">@ClusterId</span>.
+    </section>
+}
+else
+{
+    <EditForm Model="_form" OnValidSubmit="SubmitAsync" FormName="namespaceEdit">
+        <DataAnnotationsValidator />
+        <section class="panel rise" style="animation-delay:.02s">
+            <div class="panel-head">@(IsNew ? "Identity" : $"Edit {_form.NamespaceId}")</div>
+            <div style="padding:1rem">
+                <div class="mb-3">
+                    <label class="form-label" for="nsId">NamespaceId</label>
+                    <InputText id="nsId" @bind-Value="_form.NamespaceId" disabled="@(!IsNew)"
+                               class="form-control form-control-sm mono"
+                               placeholder="LINE3-equipment" />
+                </div>
+                <div class="row">
+                    <div class="col-md-6 mb-3">
+                        <label class="form-label" for="kind">Kind</label>
+                        <InputSelect id="kind" @bind-Value="_form.Kind" class="form-select form-select-sm">
+                            <option value="@NamespaceKind.Equipment">Equipment (raw signals)</option>
+                            <option value="@NamespaceKind.SystemPlatform">System Platform (Galaxy / MXAccess)</option>
+                            <option value="@NamespaceKind.Simulated">Simulated (replay — reserved)</option>
+                        </InputSelect>
+                    </div>
+                    <div class="col-md-6 mb-3">
+                        <label class="form-label" for="enabled">Enabled</label>
+                        <div class="form-check form-switch">
+                            <InputCheckbox id="enabled" @bind-Value="_form.Enabled" class="form-check-input" />
+                            <label class="form-check-label" for="enabled">Active in deployments</label>
+                        </div>
+                    </div>
+                </div>
+                <div class="mb-3">
+                    <label class="form-label" for="uri">NamespaceUri</label>
+                    <InputText id="uri" @bind-Value="_form.NamespaceUri" class="form-control form-control-sm mono"
+                               placeholder="urn:zb:warsaw-west:equipment" />
+                    <div class="form-text">Must be unique fleet-wide. Clients pin discovery here.</div>
+                </div>
+                <div class="mb-3">
+                    <label class="form-label" for="notes">Notes</label>
+                    <InputTextArea id="notes" @bind-Value="_form.Notes" class="form-control form-control-sm" rows="3" />
+                </div>
+            </div>
+        </section>
+
+        @if (!string.IsNullOrWhiteSpace(_error))
+        {
+            <div class="panel notice mt-3" style="border-color:var(--alert)">@_error</div>
+        }
+
+        <div class="mt-3 d-flex gap-2">
+            <button type="submit" class="btn btn-primary" disabled="@_busy">
+                @if (_busy) { <span class="spinner-border spinner-border-sm me-1"></span> }
+                @(IsNew ? "Create" : "Save changes")
+            </button>
+            <a href="/clusters/@ClusterId/namespaces" class="btn btn-outline-secondary">Cancel</a>
+            @if (!IsNew)
+            {
+                <button type="button" class="btn btn-outline-danger ms-auto" @onclick="DeleteAsync" disabled="@_busy">
+                    Delete
+                </button>
+            }
+        </div>
+    </EditForm>
+}
+
+@code {
+    [Parameter] public string ClusterId { get; set; } = "";
+    [Parameter] public string? NamespaceId { get; set; }
+
+    private bool IsNew => string.IsNullOrEmpty(NamespaceId);
+
+    private FormModel _form = new();
+    private Namespace? _existing;
+    private bool _loaded;
+    private bool _busy;
+    private string? _error;
+
+    protected override async Task OnInitializedAsync()
+    {
+        if (IsNew)
+        {
+            _form = new FormModel
+            {
+                NamespaceId = "",
+                Kind = NamespaceKind.Equipment,
+                NamespaceUri = "",
+                Enabled = true,
+            };
+        }
+        else
+        {
+            await using var db = await DbFactory.CreateDbContextAsync();
+            _existing = await db.Namespaces.AsNoTracking()
+                .FirstOrDefaultAsync(n => n.ClusterId == ClusterId && n.NamespaceId == NamespaceId);
+            if (_existing is not null)
+            {
+                _form = new FormModel
+                {
+                    NamespaceId = _existing.NamespaceId,
+                    Kind = _existing.Kind,
+                    NamespaceUri = _existing.NamespaceUri,
+                    Enabled = _existing.Enabled,
+                    Notes = _existing.Notes,
+                    RowVersion = _existing.RowVersion,
+                };
+            }
+        }
+        _loaded = true;
+    }
+
+    private async Task SubmitAsync()
+    {
+        _busy = true;
+        _error = null;
+        try
+        {
+            await using var db = await DbFactory.CreateDbContextAsync();
+            if (IsNew)
+            {
+                if (await db.Namespaces.AnyAsync(n => n.NamespaceId == _form.NamespaceId))
+                {
+                    _error = $"Namespace '{_form.NamespaceId}' already exists.";
+                    return;
+                }
+                db.Namespaces.Add(new Namespace
+                {
+                    NamespaceId = _form.NamespaceId,
+                    ClusterId = ClusterId,
+                    Kind = _form.Kind,
+                    NamespaceUri = _form.NamespaceUri,
+                    Enabled = _form.Enabled,
+                    Notes = string.IsNullOrWhiteSpace(_form.Notes) ? null : _form.Notes,
+                });
+            }
+            else
+            {
+                var entity = await db.Namespaces.FirstOrDefaultAsync(
+                    n => n.ClusterId == ClusterId && n.NamespaceId == NamespaceId);
+                if (entity is null)
+                {
+                    _error = "Row no longer exists.";
+                    return;
+                }
+                db.Entry(entity).Property(e => e.RowVersion).OriginalValue = _form.RowVersion;
+                entity.Kind = _form.Kind;
+                entity.NamespaceUri = _form.NamespaceUri;
+                entity.Enabled = _form.Enabled;
+                entity.Notes = string.IsNullOrWhiteSpace(_form.Notes) ? null : _form.Notes;
+            }
+            await db.SaveChangesAsync();
+            Nav.NavigateTo($"/clusters/{ClusterId}/namespaces");
+        }
+        catch (DbUpdateConcurrencyException)
+        {
+            _error = "Another user changed this namespace while you were editing. Reload to see the latest values, then re-apply your changes.";
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+        finally
+        {
+            _busy = false;
+        }
+    }
+
+    private async Task DeleteAsync()
+    {
+        if (IsNew) return;
+        _busy = true;
+        _error = null;
+        try
+        {
+            await using var db = await DbFactory.CreateDbContextAsync();
+            var entity = await db.Namespaces.FirstOrDefaultAsync(
+                n => n.ClusterId == ClusterId && n.NamespaceId == NamespaceId);
+            if (entity is null)
+            {
+                Nav.NavigateTo($"/clusters/{ClusterId}/namespaces");
+                return;
+            }
+            db.Entry(entity).Property(e => e.RowVersion).OriginalValue = _form.RowVersion;
+            db.Namespaces.Remove(entity);
+            await db.SaveChangesAsync();
+            Nav.NavigateTo($"/clusters/{ClusterId}/namespaces");
+        }
+        catch (DbUpdateConcurrencyException)
+        {
+            _error = "Another user changed this namespace while you were viewing it. Reload before deleting.";
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+        finally
+        {
+            _busy = false;
+        }
+    }
+
+    private sealed class FormModel
+    {
+        [Required, RegularExpression("^[A-Za-z0-9_-]+$", ErrorMessage = "Use letters, digits, dash, underscore.")]
+        public string NamespaceId { get; set; } = "";
+        public NamespaceKind Kind { get; set; } = NamespaceKind.Equipment;
+        [Required, RegularExpression("^urn:[A-Za-z0-9_:./-]+$", ErrorMessage = "Use a URN, e.g. urn:zb:warsaw-west:equipment.")]
+        public string NamespaceUri { get; set; } = "";
+        public bool Enabled { get; set; } = true;
+        public string? Notes { get; set; }
+        public byte[] RowVersion { get; set; } = [];
+    }
+}