chore(mcp): remove supervisor MCP entry

.context/mcp.json

@@ -1,9 +1,5 @@
 {
   "mcpServers": {
-    "knowledge": {
-      "url": "http://localhost:3100/mcp",
-      "description": "Project knowledge base — vector + graph retrieval"
-    },
     "brain": {
       "type": "http",
       "url": "https://brain-mcp.d-ma.be/mcp",
@@ -11,13 +7,6 @@
         "Authorization": "Bearer ${BRAIN_MCP_TOKEN}"
       }
     },
-    "supervisor": {
-      "type": "http",
-      "url": "https://supervisor-mcp.d-ma.be/mcp",
-      "headers": {
-        "Authorization": "Bearer ${SUPERVISOR_MCP_TOKEN}"
-      }
-    },
     "gitea": {
       "type": "http",
       "url": "https://git-mcp.d-ma.be/mcp",