fix: export CallModelInputFilter, CallModelData, ModelInputData, and RunOptions from top-level package

[rmotgi1227]

RunConfig.call_model_input_filter accepts a CallModelInputFilter callable. To implement one, callers need CallModelData and ModelInputData. These types are defined in run_config.py (and listed in its __all__), but they are not re-exported from the top-level agents package.

RunOptions (the TypedDict version of RunConfig accepted by Runner.run / Runner.run_streamed) has the same gap.

# currently breaks:
from agents import CallModelInputFilter  # ImportError
from agents import CallModelData         # ImportError
from agents import ModelInputData        # ImportError
from agents import RunOptions            # ImportError

# workaround (private module):
from agents.run_config import CallModelInputFilter, CallModelData, ModelInputData, RunOptions

The ToolOutputTrimmer extension already implements CallModelInputFilter and is documented as a public API, so users need these types to write their own filters.

The fix adds the four names to the from .run import ... block and to __all__ in src/agents/__init__.py.

[seratch]

@rmotgi1227 run_config is not a private module plus we don't intend to expose everything from top-level agents.