Establish local package workspaces

[hnordt]

Summary

• establish npm workspaces for the private @hyperkernel/kernel, @hyperkernel/sqlite, and @hyperkernel/ui packages
• move the private example application into apps/playground while preserving the root development workflow
• extract the existing SQLite connection setup into openDatabase without changing the application database boundary
• consume internal packages directly from explicit source exports and remove the intermediate UI distribution pipeline
• centralize shared tooling at the workspace root and keep package-specific checks and tests under the appropriate consumers
• document the workspace and SQLite package designs while preserving main's managed-filesystems record through sequential renumbering

Review

The conflict resolution merged main at d5cae7b. Both sides had independently claimed design record 0007, so the managed-filesystems record remains 0007 and this pull request's local-package-workspaces and SQLite-connection records are now 0008 and 0009.

The SQLite package is a low-level Node-only adapter and does not implement or bypass the command/event boundary. Because the full pull request touches a kernel-adjacent persistence boundary, it remains a draft and still requires experienced human maintainer review.

AI involvement

• Tool or agent: OpenAI Codex
• AI usage:
  • Planning
  • Implementation
  • Tests
• Overall usage level:
  • Supervised
  • Assisted
  • Automated
• Classification: Kernel and Experience
• Unresolved uncertainty and pending risk: No unresolved merge conflicts or known conflict-resolution risks. The Kernel-classified change still requires experienced human maintainer review and approval.

Validation

• git diff --check origin/main...HEAD
• npm run check
• npm run lint
• npm run test — 2 Vitest tests and 1 Playwright test passed
• npm run build