Improve Sessions directory filters

[hoangsonww]

Summary

• Replaced the Sessions directory selector with a custom searchable checkbox picker that supports multiple projects and keeps long paths usable.
• Replaced the native sort selector with the shared custom dropdown used by the Run page.
• Added repeatable cwd API filtering so multi-project selections remain server-paginated, plus API, OpenAPI, i18n, test, and documentation coverage.
• Centered remote-source/platform chips against the full session-row content so they align with status chips.

Why

The native controls limited project filtering to one directory and did not match the dashboard UI. Remote source chips were aligned against only the title line, which made them sit high when the session ID increased the row height.

Impact

Sessions can now be searched, filtered across multiple project directories, and sorted through consistent custom controls. Remote-source rows have more stable visual alignment.

Validation

• npm run test:client — 278 passing
• npm run test:server — 755 passing, 0 failing
• npm run build
• npm run openapi:yaml
• Prettier and file-header checks

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