## Description

This PR integrates recent fixes to improve skill generation and handle
viewer authentication gracefully.

- **Skill Generator**: Aligned the skill generation prompt template with
skill-creator best practices. Added explicit instructions to assume the
agent is smart, improved trigger descriptions, enforced stricter
metadata/naming rules, and prevented the generation of extraneous
boilerplate files.
- **Viewer**: Added a check in the `loadConfig` function to show a
"session expired" toast notification when receiving a 401 Unauthorized
response, preventing silent authentication failures.

Related Issue (Required):  Fixes #1434, Fixes #1424

## Type of change

Please delete options that are not relevant.

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (does not change functionality, e.g. code style
improvements, linting)
- [ ] Documentation update

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration

- [ ] Unit Test
- [x] Test Script Or Test Steps (please provide)
- Generated a new skill to verify that the output correctly follows the
updated prompt constraints (e.g., kebab-case naming, no extra files,
proper trigger keywords).
- Manually simulated a 401 response during config load in the viewer to
ensure the session expiration toast appears properly.
- [ ] Pipeline Automated API Test (please provide)

## Checklist

- [x] I have performed a self-review of my own code | 我已自行检查了自己的代码
- [x] I have commented my code in hard-to-understand areas |
我已在难以理解的地方对代码进行了注释
- [x] I have added tests that prove my fix is effective or that my
feature works | 我已添加测试以证明我的修复有效或功能正常
- [ ] I have created related documentation issue/PR in
[MemOS-Docs](https://github.com/MemTensor/MemOS-Docs) (if applicable) |
我已在 [MemOS-Docs](https://github.com/MemTensor/MemOS-Docs) 中创建了相关的文档
issue/PR（如果适用）
- [x] I have linked the issue to this PR (if applicable) | 我已将 issue
链接到此 PR（如果适用）
- [ ] I have mentioned the person who will review this PR | 我已提及将审查此 PR
的人

## Reviewer Checklist
- [x] closes #1434, closes #1424
- [ ] Made sure Checks passed
- [ ] Tests have been provided