Replace WYMEditor with the RDFa editor for XMLLiteral editing

- vendor the RDFa editor XSLT modules under xsl/rdfa-editor/ (synced
  from the RDFa-Editor repo) and import them from client.xsl
- render XMLLiteral form controls as editable div.rdfa-editor-content
  regions with hidden ol/lt inputs (imports/default.xsl)
- create the editor state container in the client main template;
  full chrome bring-up on the first region, per-region init afterwards
  via the upstream local:init-editor/local:init-region seams (form.xsl)
- serialize canonicalized editor content into the ol input in
  ldh:FormPreSubmit
- run the ldh:FormPreSubmit pass before ldh:parse-rdf-post in the block
  POST and generic row-form submit handlers (previously the param
  defaults parsed the inputs before the pass could sync them, dropping
  the empty ol and tripping the ldh:XHTML MissingValue constraint) and
  canonicalize XMLLiterals in the request body (block.xsl, form.xsl)
- chain body onmousemove to the editor's sweep-selection tracker
  which it shadowed by import precedence (navigation.xsl)
- host the singleton toolbar in a per-document editor-bar below the
  action bar (document.xsl slot + local:toolbar-host override); sticky,
  matching action-bar chrome, hidden while no editable region is open
  along with the editor breadcrumb footer (bootstrap.css)
- drop the WYMEditor assets from layout.xsl; load rdfa-editor.css
  under the same conditions instead

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: namedgraph

src/main/webapp/static/com/atomgraph/linkeddatahub/css/bootstrap.css

@@ -210,4 +210,7 @@ object { display: block; margin: auto; max-height: 400px; overflow: hidden; widt
 .ol-overlay-container { width: 60%; max-height: 75%; background-color: white; overflow: auto; }
 .ol-overlay-container img { max-width: 100%; }
 /* SVG graph specific */
-circle { cursor: move; }
+circle { cursor: move; }
+/* RDFa editor specific */
+.editor-bar { position: sticky; top: calc(var(--action-bar-top, 51px) + 50px); z-index: 998; background: #dfdfdf; padding: 0; box-shadow: none; border-top: 1px solid #aaa; }
+.editor-bar:not(:has(#edit-toolbar)), body:not(:has(.rdfa-editor-content)) .editor-bar, body:not(:has(.rdfa-editor-content)) #rdfa-editor-breadcrumb { display: none; }