fix(py): widen create_model field spec annotations for pyright

[cpsievert]

Supersedes #325, which pulled in the entire stacked ggsql-caching-reader + maps-capability history because its head branch (feat/maps-capability-py) is shared with #323. This PR contains just the pyright fix, based directly on main.

Summary

handoff_result_model() in pkg-py/src/querychat/_handoff_prompt.py builds pydantic field specs as inferred tuples. Newer pydantic stubs (with TypeForm) reject those inferred types as arguments to create_model() (reportCallIssue), which surfaced as a pyright failure on the Python 3.10 CI job. Adding explicit tuple[Any, Any] annotations widens the inferred types so the call type-checks.

The identical change is also present in #323 and #324; this PR lets it land on main immediately without waiting for the stacked feature work. The ruff cleanups that were also in #325 (de7d660d) only touch code from the stacked branches and remain with #323.

Verification

uv run pyright reports no errors for pkg-py/src/querychat/_handoff_prompt.py with this change, and uv run ruff check passes.