fix(proxy): add KG endpoint + GET query-param agent_id namespacing (DAK-6899) (#216)

Two proxy fixes to unblock playground Mode 9 (KG Explorer):

1. allowlist.js: add POST /v1/knowledge/graph/full to the sandbox allow-list.
   The playground KG Explorer calls this endpoint (not /knowledge/graph which
   requires a single memory_id). full_knowledge_graph accepts agent_id and
   builds the graph from all memories in that agent's namespace.

2. server.js: rewrite agent_id in GET URL query parameters (same session
   namespace as POST body rewriting). Without this, GET /v1/knowledge/query
   and GET /v1/knowledge/path land in a different namespace than the memories
   that were seeded via POST store — making KG traversal always return empty.

All 9 playground modes now validated end-to-end.

Co-authored-by: Paperclip <noreply@paperclip.ing>

Author: ferhimedamine

docker/playground/proxy/allowlist.js

@@ -74,6 +74,7 @@ const ALLOW = [
   // /v1/knowledge/graph is POST-only in the engine (lib.rs:483 post). The dead
   // GET entry was removed (it could only ever 405).
   compile('POST', '/v1/knowledge/graph'),
+  compile('POST', '/v1/knowledge/graph/full'),  // DAK-6899: KG Explorer
   compile('GET', '/v1/memories/{seg}/graph'),
   compile('GET', '/v1/memories/{seg}/path'),
   // NOTE: /v1/memories/{seg}/links is POST-only in the engine (link creation,

docker/playground/proxy/server.js

@@ -416,7 +416,19 @@ function createServer(config, store) {
       };
     }
 
-    forward(config, req, res, path, bodyBuf, outHeaders, rewrite);
+    // Also rewrite agent_id in URL query params for GET endpoints (DAK-6899)
+    let forwardPath = path;
+    try {
+      const qUrl = new URL(req.url, "http://localhost");
+      if (qUrl.searchParams.has("agent_id")) {
+        const namespace = sessionNamespace(resolved.id);
+        const qAgentId = qUrl.searchParams.get("agent_id");
+        qUrl.searchParams.set("agent_id", namespace);
+        forwardPath = qUrl.pathname + "?" + qUrl.searchParams.toString();
+        if (!rewrite) rewrite = { namespace, restoreTo: qAgentId };
+      }
+    } catch (_) {}
+    forward(config, req, res, forwardPath, bodyBuf, outHeaders, rewrite);
   });
 }