feat: add /jobs API

This API will be later tied to jobs as defined for specific flows
(post-training, eval, etc.) through the common scheduler mechanism.

Note: At the moment, API does nothing useful. (Except returning Not
Implemented errors when called.)

This is an alternative to developing per-flow jobs APIs. Eventually,
once /jobs API is implemented, we should be able to deprecate existing
APIs under /v1/post-training/, /v1/eval/ etc.

See #1587 (tracker)
See #1238 (design details)

Note: This is an alternative path to #1582 and #1583.

Signed-off-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>

llama_stack/distribution/jobs.py

@@ -0,0 +1,48 @@
+# 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 pydantic import BaseModel
+
+from llama_stack.apis.jobs import (
+    JobInfo,
+    Jobs,
+    ListJobsResponse,
+)
+from llama_stack.distribution.datatypes import StackRunConfig
+
+
+class DistributionJobsConfig(BaseModel):
+    run_config: StackRunConfig
+
+
+async def get_provider_impl(config, deps):
+    impl = DistributionJobsImpl(config, deps)
+    await impl.initialize()
+    return impl
+
+
+class DistributionJobsImpl(Jobs):
+    def __init__(self, config, deps):
+        self.config = config
+        self.deps = deps
+
+    async def initialize(self) -> None:
+        pass
+
+    async def shutdown(self) -> None:
+        pass
+
+    async def list_jobs(self) -> ListJobsResponse:
+        raise NotImplementedError
+
+    async def delete_job(self, job_id: str) -> None:
+        raise NotImplementedError
+
+    async def cancel_job(self, job_id: str) -> None:
+        raise NotImplementedError
+
+    async def get_job(self, job_id: str) -> JobInfo:
+        raise NotImplementedError