Split safety into (llama-guard, prompt-guard, code-scanner) (#400)

Splits the meta-reference safety implementation into three distinct providers:

- inline::llama-guard
- inline::prompt-guard
- inline::code-scanner

Note that this PR is a backward incompatible change to the llama stack server. I have added deprecation_error field to ProviderSpec -- the server reads it and immediately barfs. This is used to direct the user with a specific message on what action to perform. An automagical "config upgrade" is a bit too much work to implement right now :/

(Note that we will be gradually prefixing all inline providers with inline:: -- I am only doing this for this set of new providers because otherwise existing configuration files will break even more badly.)

llama_stack/providers/tests/safety/fixtures.py

@@ -10,15 +10,14 @@ import pytest_asyncio
 from llama_stack.apis.shields import ShieldType
 
 from llama_stack.distribution.datatypes import Api, Provider
-from llama_stack.providers.inline.safety.meta_reference import (
-    LlamaGuardShieldConfig,
-    SafetyConfig,
-)
+from llama_stack.providers.inline.safety.llama_guard import LlamaGuardConfig
+from llama_stack.providers.inline.safety.prompt_guard import PromptGuardConfig
 from llama_stack.providers.remote.safety.bedrock import BedrockSafetyConfig
-from llama_stack.providers.tests.env import get_env_or_fail
+
 from llama_stack.providers.tests.resolver import resolve_impls_for_test_v2
 
 from ..conftest import ProviderFixture, remote_stack_fixture
+from ..env import get_env_or_fail
 
 
 @pytest.fixture(scope="session")
@@ -34,17 +33,29 @@ def safety_model(request):
 
 
 @pytest.fixture(scope="session")
-def safety_meta_reference(safety_model) -> ProviderFixture:
+def safety_llama_guard(safety_model) -> ProviderFixture:
     return ProviderFixture(
         providers=[
             Provider(
-                provider_id="meta-reference",
-                provider_type="meta-reference",
-                config=SafetyConfig(
-                    llama_guard_shield=LlamaGuardShieldConfig(
-                        model=safety_model,
-                    ),
-                ).model_dump(),
+                provider_id="inline::llama-guard",
+                provider_type="inline::llama-guard",
+                config=LlamaGuardConfig(model=safety_model).model_dump(),
+            )
+        ],
+    )
+
+
+# TODO: this is not tested yet; we would need to configure the run_shield() test
+# and parametrize it with the "prompt" for testing depending on the safety fixture
+# we are using.
+@pytest.fixture(scope="session")
+def safety_prompt_guard() -> ProviderFixture:
+    return ProviderFixture(
+        providers=[
+            Provider(
+                provider_id="inline::prompt-guard",
+                provider_type="inline::prompt-guard",
+                config=PromptGuardConfig().model_dump(),
             )
         ],
     )
@@ -63,7 +74,7 @@ def safety_bedrock() -> ProviderFixture:
     )
 
 
-SAFETY_FIXTURES = ["meta_reference", "bedrock", "remote"]
+SAFETY_FIXTURES = ["llama_guard", "bedrock", "remote"]
 
 
 @pytest_asyncio.fixture(scope="session")
@@ -96,7 +107,21 @@ async def safety_stack(inference_model, safety_model, request):
 
     # Register the appropriate shield based on provider type
     provider_type = safety_fixture.providers[0].provider_type
+    shield = await create_and_register_shield(provider_type, safety_model, shields_impl)
 
+    provider_id = inference_fixture.providers[0].provider_id
+    print(f"Registering model {inference_model} with provider {provider_id}")
+    await impls[Api.models].register_model(
+        model_id=inference_model,
+        provider_id=provider_id,
+    )
+
+    return safety_impl, shields_impl, shield
+
+
+async def create_and_register_shield(
+    provider_type: str, safety_model: str, shields_impl
+):
     shield_config = {}
     shield_type = ShieldType.llama_guard
     identifier = "llama_guard"
@@ -109,10 +134,8 @@ async def safety_stack(inference_model, safety_model, request):
         shield_config["guardrailVersion"] = get_env_or_fail("BEDROCK_GUARDRAIL_VERSION")
         shield_type = ShieldType.generic_content_shield
 
-    shield = await shields_impl.register_shield(
+    return await shields_impl.register_shield(
         shield_id=identifier,
         shield_type=shield_type,
         params=shield_config,
     )
-
-    return safety_impl, shields_impl, shield