Defer tab activation until rdf-document-response populates the cache

Tab click handler and close-tab fallback eagerly called ldh:ActivateTab,
making the pane mouse-targetable before ldh:DocumentNavigate had finished
fetching the document and populating LinkedDataHub.contents[$uri]. On a
page loaded with ?uri=<external>, the local URI is never in the cache
until the user switches back, so any mousemove on a block then hit the
nested ixsl:get() in block.xsl and threw an uncaught XError, which also
killed the body-level handler that slides in the left sidebar.

ldh:RenderTab already runs ldh:ActivateTab at the end of
ldh:rdf-document-response, so the eager calls were just trading
correctness for an instant visual swap. Removing them aligns tab clicks
with how direct navigation works: cursor: progress during the fetch,
then tab-bar highlight and pane swap together once the cache is filled.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: namedgraph

src/main/webapp/static/com/atomgraph/linkeddatahub/xsl/client.xsl

@@ -1015,8 +1015,6 @@ WHERE
         <!-- proxied tab: $uri is the external target (?uri=…); local tab: $uri is the bare document URI (no query string) - matches data-uri / document-body/@about, so the cache key downstream stays consistent -->
         <xsl:variable name="uri" select="if (map:contains($query-params, 'uri')) then xs:anyURI(map:get($query-params, 'uri')) else ac:absolute-path($href)" as="xs:anyURI"/>
 
-        <xsl:apply-templates select=".." mode="ldh:ActivateTab"/>
-
         <xsl:call-template name="ldh:DocumentNavigate">
             <xsl:with-param name="uri" select="$uri"/>
             <xsl:with-param name="query-params" select="map:remove($query-params, 'uri')"/>
@@ -1040,10 +1038,8 @@ WHERE
         <!-- remove the tab <li> from the DOM -->
         <xsl:sequence select="ixsl:call($tab-li, 'remove', [])[current-date() lt xs:date('2000-01-01')]"/>
 
-        <!-- if the closed tab was active, activate the fallback and navigate to its URI -->
+        <!-- if the closed tab was active, navigate to the fallback's URI (ldh:RenderTab will activate after fetch) -->
         <xsl:if test="$was-active and $fallback-li">
-            <xsl:apply-templates select="$fallback-li" mode="ldh:ActivateTab"/>
-
             <xsl:variable name="fallback-href" select="xs:anyURI(resolve-uri($fallback-li/a/@href, ldh:base-uri(.)))" as="xs:anyURI"/>
             <xsl:variable name="fallback-query-params" select="ldh:parse-query-params(substring-after($fallback-href, '?'))" as="map(xs:string, xs:string*)"/>
             <xsl:variable name="fallback-uri" select="if (map:contains($fallback-query-params, 'uri')) then xs:anyURI(map:get($fallback-query-params, 'uri')) else ac:absolute-path($fallback-href)" as="xs:anyURI"/>