chore(workspace): track data app repository

[albert20260301]

Summary

• add altertable-ai/data-app to the supervised project inventory
• classify it as the data-app project and record its @altertable/data-app npm package metadata

Impact

The repository will be included in Albert's managed GitHub subscriptions once this inventory change merges. It remains outside SDK spec-status scans, since it is a UI/runtime package rather than a Lakehouse or Product Analytics SDK.

Validation

• jq empty repositories.config.json
• bash -n scripts/subscribe-repos.sh
• git diff --check

[albert20260301]

@francoischalifour could you review this?

I picked you because you assigned this repository's ownership. CI is green. The main review focus is whether data-app belongs in the non-SDK project inventory, with npm metadata retained for release verification.