feat(ui/templates): derived-template action and slimmer composition row

Right-click a template now offers "New Derived Template" — opens
TemplateCreate with the parent pre-selected via a new ?parentId query
parameter. Composition rows in the tree drop the trailing
"→ TargetName" muted text; the kind glyph plus the instance name carry
enough meaning, and the composed template is one click away from the
row's right-click menu.

docs/plans/2026-05-11-templates-folder-hierarchy-design.md

@@ -29,7 +29,7 @@ Inheritance is **not** rendered as tree nesting in the image, and it is not rend
 | Root-level templates | Allowed (`FolderId` nullable). Existing templates migrate with `FolderId = null`. |
 | Folder delete with contents | Blocked; structured error lists child counts. |
 | Page layout | **Tree browser only** — no split-pane editor. Selecting a template navigates to `/design/templates/{id}` (TemplateEdit page); creating navigates to `/design/templates/create`. |
-| Tree node visuals | Per `Component-TreeView.md` Visual Design Guide V7: Bootstrap Icons (`bi-folder` / `bi-folder2-open` / `bi-file-earmark-text` / `bi-arrow-return-right`), name-only labels (no count/inherit badges on template nodes), folder child-count pill, composition `→ $Target` muted secondary text. |
+| Tree node visuals | Per `Component-TreeView.md` Visual Design Guide V7: Bootstrap Icons (`bi-folder` / `bi-folder2-open` / `bi-file-earmark-text` / `bi-arrow-return-right`), name-only labels (no count/inherit badges on template nodes; composition rows also name-only — the glyph signals the kind), folder child-count pill. |
 
 ## Data model
 
@@ -144,7 +144,7 @@ private record TmplNode(
 **Inline node labels** (see `Component-TreeView.md` V7 for the canonical recipe):
 - Folder: `<i class="bi bi-folder">` (closed) or `<i class="bi bi-folder2-open">` (expanded) + name (semibold when has children) + count-pill badge of direct children.
 - Template: `<i class="bi bi-file-earmark-text">` + `$Name` (semibold when has compositions). **No** inheritance hint, **no** attr/alarm/script count, **no** composition count on the node.
-- Composition: `<i class="bi bi-arrow-return-right">` + composition instance name + muted `→ $ComposedTemplateName` secondary text.
+- Composition: `<i class="bi bi-arrow-return-right">` + composition instance name only. The composed template name is intentionally omitted from the tree — open the owning template's edit page to see/manage compositions.
 
 **Search/filter:** out of scope for v1; the underlying component supports external filtering (per `Component-TreeView.md` R8) so it can be added later without component changes.
 
@@ -160,8 +160,8 @@ private record TmplNode(
 | ▶ 📁 _Default Templates                    |
 | ▼ 📂 Dev                                   |
 |     📄 $TestMachine                        |
-|        ↪ DelmiaReceiver → $DelmiaSvc       |
-|        ↪ MESReceiver   → $MesSvc           |
+|        ↪ DelmiaReceiver                    |
+|        ↪ MESReceiver                       |
 |     📄 $TestObject                         |
 | ▶ 📁 System                                |
 | 📄 $UnfiledTemplate                        |

docs/requirements/Component-TreeView.md

@@ -425,7 +425,7 @@ Three node kinds; concrete recipes following V1–V6.
 |---|---|---|---|---|---|
 | Folder | `bi-folder` | `bi-folder2-open` | folder name (semibold when has children, regular otherwise) | — | count of direct children (subtle pill), only if ≥ 1 |
 | Template | `bi-file-earmark-text` | same (templates with compositions still use the same glyph — chevron carries state) | `$Name` (semibold when has compositions, regular otherwise) | — | none |
-| Composition | `bi-arrow-return-right` | n/a (leaf, no expanded state) | composition instance name (regular weight) | `<span class="text-muted small ms-1">→ $TargetName</span>` | none |
+| Composition | `bi-arrow-return-right` | n/a (leaf, no expanded state) | composition instance name (regular weight) | — | none |
 
 **`NodeContent` fragment** for the templates page (replaces the current `RenderNodeLabel` in `Templates.razor`):
 
@@ -452,13 +452,8 @@ Three node kinds; concrete recipes following V1–V6.
         break;
 
     case TmplNodeKind.Composition:
-        var composedName = _templates.FirstOrDefault(t => t.Id == node.Composition!.ComposedTemplateId)?.Name
-                           ?? $"#{node.Composition!.ComposedTemplateId}";
         <span class="tv-glyph"><i class="bi bi-arrow-return-right"></i></span>
-        <span class="tv-label" title="@node.Label">
-            @node.Label
-            <span class="text-muted small ms-1">→ @composedName</span>
-        </span>
+        <span class="tv-label" title="@node.Label">@node.Label</span>
         break;
 }
 ```

src/ScadaLink.CentralUI/Components/Pages/Design/TemplateCreate.razor

@@ -57,6 +57,7 @@
 
 @code {
     [SupplyParameterFromQuery] public int? FolderId { get; set; }
+    [SupplyParameterFromQuery] public int? ParentId { get; set; }
 
     private List<Template> _templates = new();
     private bool _loading = true;
@@ -71,6 +72,10 @@
         try
         {
             _templates = (await TemplateEngineRepository.GetAllTemplatesAsync()).ToList();
+            if (ParentId is int pid && _templates.Any(t => t.Id == pid))
+            {
+                _createParentId = pid;
+            }
         }
         catch (Exception ex)
         {

src/ScadaLink.CentralUI/Components/Pages/Design/Templates.razor

@@ -239,13 +239,8 @@
                 break;
 
             case TmplNodeKind.Composition:
-                var composedName = _templates.FirstOrDefault(t => t.Id == node.Composition!.ComposedTemplateId)?.Name
-                                   ?? $"#{node.Composition!.ComposedTemplateId}";
                 <span class="tv-glyph"><i class="bi bi-arrow-return-right"></i></span>
-                <span class="tv-label" title="@node.Label">
-                    @node.Label
-                    <span class="text-muted small ms-1">→ @composedName</span>
-                </span>
+                <span class="tv-label" title="@node.Label">@node.Label</span>
                 break;
         }
     };
@@ -282,6 +277,7 @@
                 break;
 
             case TmplNodeKind.Template:
+                <button class="dropdown-item" @onclick='() => NavigationManager.NavigateTo($"/design/templates/create?parentId={node.EntityId}")'>New Derived Template</button>
                 <button class="dropdown-item" @onclick="() => OpenMoveTemplateDialog(node.EntityId, node.Label)">Move to Folder…</button>
                 <div class="dropdown-divider"></div>
                 <button class="dropdown-item text-danger" @onclick="() => DeleteTemplate(node.Template!)">Delete</button>

tests/ScadaLink.CentralUI.Tests/TemplatesPageTests.cs

@@ -116,7 +116,9 @@ public class TemplatesPageTests : BunitContext
         ownerToggle!.Click();
 
         Assert.Contains("DelmiaReceiver", cut.Markup);
-        Assert.Contains("→", cut.Markup);
+        // The composition glyph appears via Bootstrap Icons; the composed template name
+        // is intentionally not rendered on the tree (V7 spec).
+        Assert.Contains("bi-arrow-return-right", cut.Markup);
     }
 
 }