fix rename session and agent

cmd/ollie-9p/main.go

@@ -355,14 +355,18 @@ func modeString(mode plan9.Perm) string {
 
 func cmdMv(oldPath, newPath string) {
 	fsys := dial()
-	// 9P Twstat renames within the parent directory. The new name must be
-	// just the leaf name, not a full path. Validate that both arguments
-	// are full paths under the same parent.
+	// Twstat takes a destination basename. Both paths must refer to the
+	// same directory; normalize redundant trailing slashes before comparing.
+	oldPath = strings.TrimRight(oldPath, "/")
+	newPath = strings.TrimRight(newPath, "/")
 	oldParent, _ := splitPath(oldPath)
 	newParent, newLeaf := splitPath(newPath)
 	if oldParent != newParent {
 		fatalf("mv: old and new paths must be in the same directory (%s != %s)", oldParent, newParent)
 	}
+	if newLeaf == "" || newLeaf == "." || newLeaf == ".." {
+		fatalf("mv: invalid destination %q", newPath)
+	}
 	if err := fsys.Wstat(oldPath, &plan9.Dir{Name: newLeaf}); err != nil {
 		fatalf("mv %s %s: %v", oldPath, newPath, err)
 	}

fs/agentfiles.go

@@ -27,7 +27,9 @@ func listAgents(ctx HandlerCtx) ([]FsNodeDecl, error) {
 			continue
 		}
 
-		dirName := a.ID()
+		// The namespace uses the mutable agent name. The immutable ID remains
+		// available through the id file and is used for the log map.
+		dirName := a.Name()
 
 		agentDir := Dir(dirName,
 			// prompt — submit a prompt to the agent

fs/sessionfiles.go

@@ -132,6 +132,9 @@ func listSessions(ctx HandlerCtx) ([]FsNodeDecl, error) {
 				}),
 			),
 		)
+		// Dynamic session directories must expose the lifecycle rename operation.
+		// Without this, Tree.Rename finds the directory but reports “rename not supported”.
+		sessionDir.Rename = func(newName string) error { return rename(newName) }
 		out = append(out, sessionDir)
 	}
 	return out, nil