[Test] CI: add v2 migration resolver coverage with local Postgres

Adds end-to-end CI coverage for `--use_v2_migration_resolver` via a new
job `installing_litellm_on_python_v2_migration_resolver`:

- Clones the pytest smoke path from `installing_litellm_on_python` but
  uses a local Postgres sidecar instead of the shared DB to prevent
  collisions with the v1 variant.
- Runs only the new `test_litellm_proxy_server_config_no_general_settings_v2_resolver`
  which spawns the proxy with `--use_v2_migration_resolver` and smoke-tests
  `/health/liveliness` and `/chat/completions`.

Refactors `test_basic_python_version.py`:

- Extracts the proxy spawn + smoke-test body into `_run_proxy_server_smoke_test`
  so the v1 and v2 tests share the same code path.
- The existing `test_litellm_proxy_server_config_no_general_settings` is
  now a thin wrapper that passes no extra args (v1 default, unchanged).
- Adds `..._v2_resolver` variant that passes `--use_v2_migration_resolver`.

The existing `installing_litellm_on_python` / `installing_litellm_on_python_3_13`
jobs filter out the v2 variant via `-k "not v2_resolver"` so they keep
running only against their shared DB, unchanged behavior.

.circleci/config.yml

@@ -1529,7 +1529,50 @@ jobs:
           command: |
             pwd
             ls
-            uv run --no-sync python -m pytest -vv tests/local_testing/test_basic_python_version.py
+            uv run --no-sync python -m pytest -vv tests/local_testing/test_basic_python_version.py -k "not v2_resolver"
+
+  installing_litellm_on_python_v2_migration_resolver:
+    docker:
+      - image: cimg/python:3.11
+        auth:
+          username: ${DOCKERHUB_USERNAME}
+          password: ${DOCKERHUB_PASSWORD}
+      - image: cimg/postgres:16.0
+        environment:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: litellm_test
+    working_directory: ~/project
+    environment:
+      DATABASE_URL: "postgresql://postgres:postgres@localhost:5432/litellm_test"
+
+    steps:
+      - checkout
+      - setup_google_dns
+      - run:
+          name: Install Dependencies
+          command: |
+            curl -LsSf -o /tmp/uv-install.sh https://astral.sh/uv/0.10.9/install.sh
+            echo "7fc46e39cb97290b57169c0c813a17970585ac519139f19006453c99b5f2f45f  /tmp/uv-install.sh" | sha256sum -c -
+            env UV_NO_MODIFY_PATH=1 sh /tmp/uv-install.sh
+            rm -f /tmp/uv-install.sh
+            echo 'export PATH="$HOME/.local/bin:$PATH"' >> "$BASH_ENV"
+            export PATH="$HOME/.local/bin:$PATH"
+            if [ -f "$HOME/miniconda/etc/profile.d/conda.sh" ]; then
+              export PATH="$HOME/miniconda/bin:$PATH"
+              source "$HOME/miniconda/etc/profile.d/conda.sh"
+              conda activate myenv
+            fi
+            uv sync --frozen --all-groups --all-extras --python "$(which python)"
+      - setup_litellm_enterprise_pip
+      - wait_for_service:
+          url: tcp://localhost:5432
+          timeout: "60"
+      - run:
+          name: Run v2 migration resolver proxy smoke test
+          command: |
+            uv run --no-sync python -m pytest -vv \
+              tests/local_testing/test_basic_python_version.py::test_litellm_proxy_server_config_no_general_settings_v2_resolver
 
   installing_litellm_on_python_3_13:
     docker:
@@ -1563,7 +1606,7 @@ jobs:
           command: |
             pwd
             ls
-            uv run --no-sync python -m pytest -v tests/local_testing/test_basic_python_version.py
+            uv run --no-sync python -m pytest -v tests/local_testing/test_basic_python_version.py -k "not v2_resolver"
   helm_chart_testing:
     machine:
       image: ubuntu-2204:2023.10.1 # Use machine executor instead of docker
@@ -3544,6 +3587,12 @@ workflows:
               only:
                 - main
                 - /litellm_.*/
+      - installing_litellm_on_python_v2_migration_resolver:
+          filters:
+            branches:
+              only:
+                - main
+                - /litellm_.*/
       - helm_chart_testing:
           requires:
             - build_docker_database_image

tests/local_testing/test_basic_python_version.py

@@ -100,8 +100,12 @@ import pytest
 import requests
 
 
-def test_litellm_proxy_server_config_no_general_settings():
-    # Sync the local litellm packages into the project environment
+def _run_proxy_server_smoke_test(extra_proxy_args=None):
+    """Sync deps, generate Prisma client, start proxy with optional extra args,
+    send a health check + chat/completions request, and tear down."""
+    if extra_proxy_args is None:
+        extra_proxy_args = []
+
     server_process = None
     try:
         _run_uv(
@@ -144,6 +148,7 @@ def test_litellm_proxy_server_config_no_general_settings():
                 "litellm.proxy.proxy_cli",
                 "--config",
                 config_fp,
+                *extra_proxy_args,
             ],
             cwd=PROJECT_ROOT,
         )
@@ -182,3 +187,17 @@ def test_litellm_proxy_server_config_no_general_settings():
 
     # Additional assertions can be added here
     assert True
+
+
+def test_litellm_proxy_server_config_no_general_settings():
+    """Exercises the default (v1) migration resolver."""
+    _run_proxy_server_smoke_test()
+
+
+def test_litellm_proxy_server_config_no_general_settings_v2_resolver():
+    """Exercises the opt-in v2 migration resolver.
+
+    Runs in a separate CI job against a local Postgres to avoid collisions
+    with the v1 variant when they share a database.
+    """
+    _run_proxy_server_smoke_test(extra_proxy_args=["--use_v2_migration_resolver"])