[python] Emit TypedDicts as a patchable types/ package

[Copilot]

TypedDict generation currently emits a standalone types.py, which makes customization inconsistent with the existing patchable models/ layout. This change moves TypedDict output into a types/ package so generated type surfaces can be patched without editing generated files directly.

• Generate a patchable types/ package

  • Replace per-namespace types.py with:
    • types/__init__.py
    • types/_types.py
    • types/_patch.py
  • Keep the public import surface stable through types/__init__.py while isolating generated content in _types.py.

• Update TypedDict import resolution

  • Adjust type and enum import generation to resolve correctly from within the nested types package.
  • Preserve same-namespace vs cross-namespace behavior for TypedDicts, enums, and model references.

• Clean up legacy output on regen

  • Remove stale top-level types.py when regenerating into the new package layout to avoid duplicate or conflicting type surfaces.

• Add focused coverage

  • Add unit tests for the new generated file structure and legacy types.py cleanup behavior.

Example generated layout:

from sample.types import WidgetUpdate

sample/
  types/
    __init__.py
    _types.py
    _patch.py

• Fixes [python] emit typeddicts in a folder /types/ to allow for patching #11356

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npm i https://pkg.pr.new/@typespec/http-client-python@11370

commit: 271cb7b

[github-actions]

Python emitter diff

Baseline gh:4da8bc856581babb8cb705ed9a0199141dff296b vs this PR.

Diff summary: 378 file(s), +6716 / -43

Rendered diff: inline on the run summary, or the emitter-diff-html artifact.

Informational check (eng/emitter-diff); does not block the PR.

[github-actions]

All changed packages have been documented.

• ✅ @typespec/http-client-python

Show changes

@typespec/http-client-python - fix ✏️

Generate TypedDict outputs in a patchable types/ package with _types.py and _patch.py instead of a standalone types.py file.