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.
Templates page is now a tree-only browser; editing happens on a dedicated
TemplateEdit page. Drag-drop is replaced by context-menu Move-to-Folder.
TreeView gains Bootstrap Icons (chevron + per-kind glyphs), ancestor guide
lines, defined hover/selected/focus tokens, and Escape-dismisses-menu per
the new Visual Design Guide (V1-V7) in Component-TreeView.md.
Replaces the current /design/templates list view with a Wonderware-style
template toolbox: nested TemplateFolder entity, FolderId on Template,
composition children as inline tree leaves, persistent split-pane with
editor on the right, context menus + drag-drop reorg.
