Simplify codebase per audit of 8b89f14

internal/agents/fork.go

@@ -42,15 +42,10 @@ func (m *Manager) forkTool(l *live) mcp.Tool {
 			"title": {"type": "string", "description": "The new task's title, naming the path it takes."},
 			"prompt": {"type": "string", "description": "The forked agent's next message: tell it that it is the other side of a fork and which path to take."}
 		}, "required": ["title", "prompt"]}`),
-		Handler: func(ctx context.Context, raw json.RawMessage) (string, error) {
-			args := struct {
-				Title  string `json:"title"`
-				Prompt string `json:"prompt"`
-			}{}
-			err := json.Unmarshal(raw, &args)
-			if err != nil {
-				return "", fmt.Errorf("malformed fork call: %w", err)
-			}
+		Handler: mcp.Typed(func(ctx context.Context, args struct {
+			Title  string `json:"title"`
+			Prompt string `json:"prompt"`
+		}) (string, error) {
 			if strings.TrimSpace(args.Title) == "" || strings.TrimSpace(args.Prompt) == "" {
 				return "", errors.New("title and prompt are required")
 			}
@@ -88,7 +83,7 @@ func (m *Manager) forkTool(l *live) mcp.Tool {
 			slog.Info("task forked by its agent", "task", src.Id, "fork", t.Id, "snapshot", snap.N)
 			return fmt.Sprintf("Forked at snapshot #%d as task %s %q, branch %s, worktree %s; its agent continues from just before this call with your prompt. Carry on here with your own path.",
 				snap.N, t.Id, t.Title, t.Branch, t.WorktreePath), nil
-		},
+		}),
 	}
 }