feat: split API and provider specs into separate llama-stack-api pkg

Extract API definitions, models, and provider specifications into a
standalone llama-stack-api package that can be published to PyPI
independently of the main llama-stack server.

Motivation

External providers currently import from llama-stack, which overrides
the installed version and causes dependency conflicts. This separation
allows external providers to:

- Install only the type definitions they need without server dependencies
- Avoid version conflicts with the installed llama-stack package
- Be versioned and released independently

This enables us to re-enable external provider module tests that were
previously blocked by these import conflicts.

Changes

- Created llama-stack-api package with minimal dependencies (pydantic, jsonschema)
- Moved APIs, providers datatypes, strong_typing, and schema_utils
- Updated all imports from llama_stack.* to llama_stack_api.*
- Preserved git history using git mv for moved files
- Configured local editable install for development workflow
- Updated linting and type-checking configuration for both packages
- Rebased on top of upstream src/ layout changes

Testing

Package builds successfully and can be imported independently.
All pre-commit hooks pass with expected exclusions maintained.

Next Steps

- Publish llama-stack-api to PyPI
- Update external provider dependencies
- Re-enable external provider module tests

Signed-off-by: Charlie Doern <cdoern@redhat.com>

tests/integration/vector_io/test_openai_vector_stores.py

@@ -8,10 +8,10 @@ import time
 from io import BytesIO
 
 import pytest
+from llama_stack_api.apis.vector_io import Chunk
 from llama_stack_client import BadRequestError
 from openai import BadRequestError as OpenAIBadRequestError
 
-from llama_stack.apis.vector_io import Chunk
 from llama_stack.core.library_client import LlamaStackAsLibraryClient
 from llama_stack.log import get_logger
 
@@ -645,7 +645,7 @@ def test_openai_vector_store_attach_file(
 ):
     """Test OpenAI vector store attach file."""
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     compat_client = compat_client_with_empty_stores
 
@@ -709,7 +709,7 @@ def test_openai_vector_store_attach_files_on_creation(
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
 
     compat_client = compat_client_with_empty_stores
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     # Create some files and attach them to the vector store
     valid_file_ids = []
@@ -774,7 +774,7 @@ def test_openai_vector_store_list_files(
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
 
     compat_client = compat_client_with_empty_stores
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     # Create a vector store
     vector_store = compat_client.vector_stores.create(
@@ -866,7 +866,7 @@ def test_openai_vector_store_retrieve_file_contents(
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
 
     compat_client = compat_client_with_empty_stores
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     # Create a vector store
     vector_store = compat_client.vector_stores.create(
@@ -927,7 +927,7 @@ def test_openai_vector_store_delete_file(
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
 
     compat_client = compat_client_with_empty_stores
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     # Create a vector store
     vector_store = compat_client.vector_stores.create(
@@ -993,7 +993,7 @@ def test_openai_vector_store_delete_file_removes_from_vector_store(
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
 
     compat_client = compat_client_with_empty_stores
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     # Create a vector store
     vector_store = compat_client.vector_stores.create(
@@ -1045,7 +1045,7 @@ def test_openai_vector_store_update_file(
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
 
     compat_client = compat_client_with_empty_stores
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     # Create a vector store
     vector_store = compat_client.vector_stores.create(
@@ -1102,7 +1102,7 @@ def test_create_vector_store_files_duplicate_vector_store_name(
     This test confirms that client.vector_stores.create() creates a unique ID
     """
     skip_if_provider_doesnt_support_openai_vector_stores(client_with_models)
-    from llama_stack.apis.files import ExpiresAfter
+    from llama_stack_api.apis.files import ExpiresAfter
 
     compat_client = compat_client_with_empty_stores
 

tests/integration/vector_io/test_vector_io.py

@@ -5,8 +5,7 @@
 # the root directory of this source tree.
 
 import pytest
-
-from llama_stack.apis.vector_io import Chunk
+from llama_stack_api.apis.vector_io import Chunk
 
 from ..conftest import vector_provider_wrapper