feat: add batch select and operations for task list

- Add checkbox for each task item
- Add select all checkbox in toolbar
- Add batch cancel button for selected running/waiting tasks
- Add batch delete button for selected completed/failed tasks
- Show selected count in toolbar

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/configs/env.md

@@ -0,0 +1,35 @@
+# environment
+
+**The current system is Windows.**
+
+## go env:
+
+**C:\Program Files\Go\bin**
+
+## git env:
+
+**C:\Program Files\PortableGit\bin**
+
+## python env:
+
+**C:\Program Files\Python314**
+
+**C:\Program Files\Python314\Scripts**
+
+**Please locate the venv or .venv directory in your project to create a Python virtual environment.**
+
+## node env
+
+**C:\Program Files\nodejs**
+
+## nmap env:
+
+**C:\Program Files (x86)\Nmap**
+
+## sqliet3 env:
+
+**C:\Program Files\sqlite-tools-win-x64-3510300**
+
+## curl env:
+
+**C:\Program Files\curl-8.19.0_2-win64-mingw\bin**