refactor(stage-ui): use public package exports

[leaft]

Description

@proj-airi/stage-ui bypassed two public package boundaries:

• Stage.vue imported useSettingsLive2d from the stage-ui-live2d source tree.
• The MCP store imported useLocalStorageManualReset from the stage-shared source tree.

This PR replaces both source-tree imports with their existing public package entries:

• @proj-airi/stage-ui-live2d
• @proj-airi/stage-shared/composables

This keeps package consumers independent from another package's internal file layout.

Linked Issues

None.

Additional Context

There is no runtime or visual behavior change.

Verification:

• sem diff --staged --no-cosmetics -v --file-exts .ts .tsx
• sem diff --staged --no-cosmetics -v --file-exts .vue
• pnpm -F @proj-airi/stage-ui typecheck
• pnpm lint — 0 errors and 7 existing warnings outside this change
• git diff --check

The full workspace pnpm typecheck was also run. In the isolated worktree it stopped in unchanged electron-vueuse because the generated electron-eventa output was not present. The affected package type check above passed.

[github-actions]

⏳ Approval required for deploying to Cloudflare Workers (Preview) for stage-web.

Name	Link
🔭 Waiting for approval	For maintainers, approve here

Hey, maintainers, kindly take some time to review and approve this deployment when you are available. Thank you! 🙏

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 9e46cf2a2b

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: e5bad29278

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[nekomeowww]

Thanks! I miss you so much, thanks for refactoring so many PRs.