feat: More verbose logging on workflow logs

proto/vantage/v1/vantage.proto

@@ -92,9 +92,16 @@ message ServerCommand {
     UpdateAgentCmd  update_agent  = 4;
     ApplyUpdatesCmd apply_updates = 5;
     RunStepCmd      run_step      = 6;
+    CleanupWorkspaceCmd cleanup_workspace = 7;
   }
 }
 
+// CleanupWorkspaceCmd tells the agent to recursively remove the run's working
+// directory once all steps on that server have finished.
+message CleanupWorkspaceCmd {
+  string workspace_id = 1;
+}
+
 message DeleteKeyCmd {
   string label = 1;
 }
@@ -117,6 +124,7 @@ message RunStepCmd {
   string script           = 2;
   map<string, string> env = 3;
   int32  timeout_seconds  = 4;
+  string workspace_id     = 5; // per-run working dir the agent creates & uses as cwd
 }
 
 message StepResult {