Add missing Chronus entry for packages changed in Check Changes job

[Copilot]

The Check Changes GitHub Actions job failed because pnpm chronus verify --since main detected undocumented package updates. The failure was specifically caused by changes under @typespec/emitter-framework and @typespec/http-client-python without a corresponding Chronus entry.

• Changelog compliance update

  • Added a single Chronus change file at .chronus/changes/enum-to-ts-2026-06-02.md.
  • Marked the change as internal and scoped it to:
    • @typespec/emitter-framework
    • @typespec/http-client-python

• Why this resolves the CI failure

  • The Check Changes gate requires every changed package to be documented via Chronus metadata; this PR adds the missing documentation artifact expected by that gate.

---
changeKind: internal
packages:
  - "@typespec/emitter-framework"
  - "@typespec/http-client-python"
---

Refine Python enum generation plumbing in emitter-framework and http-client-python.