Move proxy logic from ProxiedGraph into ProxyRequestFilter

Replace the JAX-RS sub-resource (ProxiedGraph) and Dispatcher routing
with a @PreMatching ContainerRequestFilter (priority 4050) that intercepts
all proxy requests — both explicit ?uri= params and lapp:Dataset matches —
before AuthorizationFilter runs. ACL is no longer checked for proxy
requests; access control is enforced by the target endpoint.

Removes the proxy bypass hack from AuthorizationFilter and simplifies
Dispatcher (no more getProxyClass()). ProxiedGraph is deleted entirely.

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

Author: namedgraph

http-tests/proxy/POST-proxied-query-no-writers.sh

@@ -101,6 +101,7 @@
 import com.atomgraph.linkeddatahub.server.factory.OntologyFactory;
 import com.atomgraph.linkeddatahub.server.factory.ServiceFactory;
 import com.atomgraph.linkeddatahub.server.filter.request.OntologyFilter;
+import com.atomgraph.linkeddatahub.server.filter.request.ProxyRequestFilter;
 import com.atomgraph.linkeddatahub.server.filter.request.AuthorizationFilter;
 import com.atomgraph.linkeddatahub.server.filter.request.ContentLengthLimitFilter;
 import com.atomgraph.linkeddatahub.server.filter.request.auth.ProxiedWebIDFilter;
@@ -1098,6 +1099,7 @@ protected void registerContainerRequestFilters()
         register(ApplicationFilter.class);
         register(OntologyFilter.class);
         register(ProxiedWebIDFilter.class);
+        register(ProxyRequestFilter.class);
         register(AuthorizationFilter.class);
         if (getMaxContentLength() != null) register(new ContentLengthLimitFilter(getMaxContentLength()));
         register(new RDFPostMediaTypeInterceptor()); // for application/x-www-form-urlencoded

src/main/java/com/atomgraph/linkeddatahub/Application.java

@@ -16,7 +16,6 @@
  */
 package com.atomgraph.linkeddatahub.server.filter.request;
 
-import com.atomgraph.client.vocabulary.AC;
 import com.atomgraph.linkeddatahub.apps.model.EndUserApplication;
 import com.atomgraph.linkeddatahub.client.SesameProtocolClient;
 import com.atomgraph.linkeddatahub.server.exception.auth.AuthorizationException;
@@ -106,18 +105,6 @@ public void filter(ContainerRequestContext request) throws IOException
         if (request == null) throw new IllegalArgumentException("ContainerRequestContext cannot be null");
         if (log.isDebugEnabled()) log.debug("Authorizing request URI: {}", request.getUriInfo().getRequestUri());
 
-        // allow proxied URIs - ACL is enforced by the target endpoint
-        // SSRF protection is handled separately in ProxiedGraph via URLValidator
-        // LDH's document-centric ACL (acl:accessTo <document>) is not meaningful for the proxy,
-        // which is a global transport function, not a document. Requiring acl:Write on a local
-        // document just to forward a DELETE to a remote target would be a security anti-pattern.
-        if (request.getUriInfo().getQueryParameters().containsKey(AC.uri.getLocalName()))
-        {
-            String proxiedURI = request.getUriInfo().getQueryParameters().getFirst(AC.uri.getLocalName());
-            if (getSystem().getDataManager().isMapped(proxiedURI)) return; // mapped local file
-            return; // external URI — skip ACL, target enforces its own access control
-        }
-
         Resource accessMode = ACCESS_MODES.get(request.getMethod());
         if (log.isDebugEnabled()) log.debug("Request method: {} ACL access mode: {}", request.getMethod(), accessMode);
         if (accessMode == null)
@@ -135,8 +122,6 @@ public void filter(ContainerRequestContext request) throws IOException
             }
         }
 
-        if (getDataset().isPresent()) return; // skip proxied dataspaces
-
         final Agent agent;
         if (request.getSecurityContext().getUserPrincipal() instanceof Agent) agent = ((Agent)(request.getSecurityContext().getUserPrincipal()));
         else agent = null; // public access
@@ -463,4 +448,4 @@ public ParameterizedSparqlString getOwnerACLQuery()
         return ownerAclQuery.copy();
     }
 
-}
+}