fix: patch SDK models for float state sequence and expandable work item fields (#84)

* fix: patch SDK models for float state sequence and expandable work item fields (#83)

Fix two Pydantic validation bugs:

1. list_states fails because the API returns sequence as a float (the Django
   model uses FloatField), but the SDK model expects int.

2. list_work_items with expand=state fails because the API returns expanded
   state objects (dicts), but the SDK WorkItem model expects state to be a
   plain UUID string.

Both fixes are applied as runtime patches to the plane-sdk Pydantic models
in a new patches.py module, which is called at package import time. The
patches update model field annotations and rebuild validators so the SDK
models match what the Plane API actually returns.

Closes #83

* chore: bump version to 0.2.6

* refactor: remove runtime patches, depend on plane-sdk 0.2.7 for fixes

* chore: update uv.lock for plane-sdk 0.2.7