harness: discover slash commands per workspace, so project skills reach the popup

crates/doc/src/parts.rs

@@ -410,9 +410,10 @@ pub fn fold_event_into_parts(out: &mut Vec<MessagePart>, event: &AgentEvent) {
                 }
             }
         }
-        // AvailableCommands feeds the engine's per-harness command cache, not
-        // the transcript. UserMessage becomes its own doc ENTRY (the engine's
-        // subagent sink writes it), never a part of the assistant message.
+        // AvailableCommands feeds the engine's per-workspace command cache
+        // (`engine::commands`), not the transcript. UserMessage becomes its own
+        // doc ENTRY (the engine's subagent sink writes it), never a part of the
+        // assistant message.
         AgentEvent::AssistantMessageCompleted { .. }
         | AgentEvent::Usage { .. }
         | AgentEvent::AvailableCommands { .. }