fix: add ChatUIProject & SessionProjectRelation to shared constants & test cases

[RC-CHN]

Will fix #7376

Modifications / 改动点

This PR fixes a backup/restore issue where WebChat project data was not included in the shared backup model registry.

Core changes:

Added chatui_projects and session_project_relations to the backup model mapping in astrbot/core/backup/constants.py
Updated backup-related test expectations in tests/test_backup.py
As a result, WebChat projects and their session relationships can now be exported and restored correctly.

• This is NOT a breaking change. / 这不是一个破坏性变更。

Screenshots or Test Results / 运行截图或测试结果

---

Checklist / 检查清单

• 😊 If there are new features added in the PR, I have discussed it with the authors through issues/emails, etc.
  / 如果 PR 中有新加入的功能，已经通过 Issue / 邮件等方式和作者讨论过。

• 👀 My changes have been well-tested, and "Verification Steps" and "Screenshots" have been provided above.
  / 我的更改经过了良好的测试，并已在上方提供了“验证步骤”和“运行截图”。

• 🤓 I have ensured that no new dependencies are introduced, OR if new dependencies are introduced, they have been added to the appropriate locations in requirements.txt and pyproject.toml.
  / 我确保没有引入新依赖库，或者引入了新依赖库的同时将其添加到 requirements.txt 和 pyproject.toml 文件相应位置。

• 😮 My changes do not introduce malicious code.
  / 我的更改没有引入恶意代码。

Summary by Sourcery

Ensure WebChat project data is included in the shared backup/restore model registry.

Bug Fixes:

• Include ChatUIProject and SessionProjectRelation tables in the backup model mapping so WebChat projects and their session relations are backed up and restored correctly.

Tests:

• Update backup model expectations to cover the new WebChat project and session relation tables in the main DB models test.

[sourcery-ai]

Hey - I've reviewed your changes and they look great!

---

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

• X
• Mastodon
• LinkedIn
• Facebook

_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}

[gemini-code-assist]

Code Review

This pull request integrates ChatUIProject and SessionProjectRelation into the backup system by updating the core constants and the associated test suite. The review feedback identifies an opportunity to improve test coverage by including several other missing tables in the expected_tables list to ensure all models defined in the backup process are correctly tracked.

[gemini-code-assist]

While adding chatui_projects and session_project_relations is correct, the expected_tables list is still missing several other tables that are currently defined in MAIN_DB_MODELS (specifically persona_folders, platform_message_history, platform_sessions, command_configs, and command_conflicts). To ensure the test provides full coverage and correctly tracks all models included in the backup process, it is recommended to include all keys from MAIN_DB_MODELS in this list.

            "persona_folders",
            "platform_message_history",
            "platform_sessions",
            "chatui_projects",
            "session_project_relations",
            "command_configs",
            "command_conflicts",