API Updates (#73)

* API Keys passed from Client instead of distro configuration

* delete distribution registry

* Rename the "package" word away

* Introduce a "Router" layer for providers

Some providers need to be factorized and considered as thin routing
layers on top of other providers. Consider two examples:

- The inference API should be a routing layer over inference providers,
  routed using the "model" key
- The memory banks API is another instance where various memory bank
  types will be provided by independent providers (e.g., a vector store
  is served by Chroma while a keyvalue memory can be served by Redis or
  PGVector)

This commit introduces a generalized routing layer for this purpose.

* update `apis_to_serve`

* llama_toolchain -> llama_stack

* Codemod from llama_toolchain -> llama_stack

- added providers/registry
- cleaned up api/ subdirectories and moved impls away
- restructured api/api.py
- from llama_stack.apis.<api> import foo should work now
- update imports to do llama_stack.apis.<api>
- update many other imports
- added __init__, fixed some registry imports
- updated registry imports
- create_agentic_system -> create_agent
- AgenticSystem -> Agent

* Moved some stuff out of common/; re-generated OpenAPI spec

* llama-toolchain -> llama-stack (hyphens)

* add control plane API

* add redis adapter + sqlite provider

* move core -> distribution

* Some more toolchain -> stack changes

* small naming shenanigans

* Removing custom tool and agent utilities and moving them client side

* Move control plane to distribution server for now

* Remove control plane from API list

* no codeshield dependency randomly plzzzzz

* Add "fire" as a dependency

* add back event loggers

* stack configure fixes

* use brave instead of bing in the example client

* add init file so it gets packaged

* add init files so it gets packaged

* Update MANIFEST

* bug fix

---------

Co-authored-by: Hardik Shah <hjshah@fb.com>
Co-authored-by: Xi Yan <xiyan@meta.com>
Co-authored-by: Ashwin Bharambe <ashwin@meta.com>

llama_stack/providers/impls/meta_reference/safety/shields/base.py

@@ -0,0 +1,58 @@
+# 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 abc import ABC, abstractmethod
+from typing import List
+
+from llama_models.llama3.api.datatypes import interleaved_text_media_as_str, Message
+from llama_stack.apis.safety import *  # noqa: F403
+
+CANNED_RESPONSE_TEXT = "I can't answer that. Can I help with something else?"
+
+
+class ShieldBase(ABC):
+    def __init__(
+        self,
+        on_violation_action: OnViolationAction = OnViolationAction.RAISE,
+    ):
+        self.on_violation_action = on_violation_action
+
+    @abstractmethod
+    def get_shield_type(self) -> ShieldType:
+        raise NotImplementedError()
+
+    @abstractmethod
+    async def run(self, messages: List[Message]) -> ShieldResponse:
+        raise NotImplementedError()
+
+
+def message_content_as_str(message: Message) -> str:
+    return interleaved_text_media_as_str(message.content)
+
+
+# For shields that operate on simple strings
+class TextShield(ShieldBase):
+    def convert_messages_to_text(self, messages: List[Message]) -> str:
+        return "\n".join([message_content_as_str(m) for m in messages])
+
+    async def run(self, messages: List[Message]) -> ShieldResponse:
+        text = self.convert_messages_to_text(messages)
+        return await self.run_impl(text)
+
+    @abstractmethod
+    async def run_impl(self, text: str) -> ShieldResponse:
+        raise NotImplementedError()
+
+
+class DummyShield(TextShield):
+    def get_shield_type(self) -> ShieldType:
+        return "dummy"
+
+    async def run_impl(self, text: str) -> ShieldResponse:
+        # Dummy return LOW to test e2e
+        return ShieldResponse(
+            shield_type=BuiltinShield.third_party_shield, is_violation=False
+        )