fix: rename llama_stack_api dir (#4155)

# What does this PR do?

the directory structure was src/llama-stack-api/llama_stack_api

instead it should just be src/llama_stack_api to match the other
packages.

update the structure and pyproject/linting config

---------

Signed-off-by: Charlie Doern <cdoern@redhat.com>
Co-authored-by: Ashwin Bharambe <ashwin.bharambe@gmail.com>

src/llama_stack_api/batches.py

@@ -0,0 +1,96 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import Literal, Protocol, runtime_checkable
+
+from pydantic import BaseModel, Field
+
+from llama_stack_api.schema_utils import json_schema_type, webmethod
+from llama_stack_api.version import LLAMA_STACK_API_V1
+
+try:
+    from openai.types import Batch as BatchObject
+except ImportError as e:
+    raise ImportError("OpenAI package is required for batches API. Please install it with: pip install openai") from e
+
+
+@json_schema_type
+class ListBatchesResponse(BaseModel):
+    """Response containing a list of batch objects."""
+
+    object: Literal["list"] = "list"
+    data: list[BatchObject] = Field(..., description="List of batch objects")
+    first_id: str | None = Field(default=None, description="ID of the first batch in the list")
+    last_id: str | None = Field(default=None, description="ID of the last batch in the list")
+    has_more: bool = Field(default=False, description="Whether there are more batches available")
+
+
+@runtime_checkable
+class Batches(Protocol):
+    """
+    The Batches API enables efficient processing of multiple requests in a single operation,
+    particularly useful for processing large datasets, batch evaluation workflows, and
+    cost-effective inference at scale.
+
+    The API is designed to allow use of openai client libraries for seamless integration.
+
+    This API provides the following extensions:
+     - idempotent batch creation
+
+    Note: This API is currently under active development and may undergo changes.
+    """
+
+    @webmethod(route="/batches", method="POST", level=LLAMA_STACK_API_V1)
+    async def create_batch(
+        self,
+        input_file_id: str,
+        endpoint: str,
+        completion_window: Literal["24h"],
+        metadata: dict[str, str] | None = None,
+        idempotency_key: str | None = None,
+    ) -> BatchObject:
+        """Create a new batch for processing multiple API requests.
+
+        :param input_file_id: The ID of an uploaded file containing requests for the batch.
+        :param endpoint: The endpoint to be used for all requests in the batch.
+        :param completion_window: The time window within which the batch should be processed.
+        :param metadata: Optional metadata for the batch.
+        :param idempotency_key: Optional idempotency key. When provided, enables idempotent behavior.
+        :returns: The created batch object.
+        """
+        ...
+
+    @webmethod(route="/batches/{batch_id}", method="GET", level=LLAMA_STACK_API_V1)
+    async def retrieve_batch(self, batch_id: str) -> BatchObject:
+        """Retrieve information about a specific batch.
+
+        :param batch_id: The ID of the batch to retrieve.
+        :returns: The batch object.
+        """
+        ...
+
+    @webmethod(route="/batches/{batch_id}/cancel", method="POST", level=LLAMA_STACK_API_V1)
+    async def cancel_batch(self, batch_id: str) -> BatchObject:
+        """Cancel a batch that is in progress.
+
+        :param batch_id: The ID of the batch to cancel.
+        :returns: The updated batch object.
+        """
+        ...
+
+    @webmethod(route="/batches", method="GET", level=LLAMA_STACK_API_V1)
+    async def list_batches(
+        self,
+        after: str | None = None,
+        limit: int = 20,
+    ) -> ListBatchesResponse:
+        """List all batches for the current user.
+
+        :param after: A cursor for pagination; returns batches after this batch ID.
+        :param limit: Number of batches to return (default 20, max 100).
+        :returns: A list of batch objects.
+        """
+        ...