refactor(mcp): delete the unwired V1PerUserTokenStore adapter (step 1b piece 5)

Piece 4 replaced V1PerUserTokenStore with the v2-native chain at the composition root, leaving the
adapter with no callers, so remove it and its test. The shared v1 read/refresh core
(resolve_user_oauth_access_token and friends) stays - delegate's egress in server.py still uses it -
and comes out with the delegate migration.

litellm/proxy/_experimental/mcp_server/outbound_credentials/v1_token_store.py

@@ -1,49 +0,0 @@
-"""v1-backed ``OAuthTokenStore`` source for the ``authorization_code`` mode.
-
-Resolves the user's access token through v1's egress core (``resolve_user_oauth_access_token``:
-Redis cache, else DB read with refresh), so the v2 arm injects exactly the token v1 would, with the
-same silent refresh. This is the strangler adapter; step 1b swaps the core for a v2-native store
-behind the same ``OAuthTokenStore`` seam. It imports v1, so it is kept out of the package
-``__init__`` like the rest of the adapter layer.
-"""
-
-from __future__ import annotations
-
-from collections.abc import Callable
-from typing import TYPE_CHECKING
-
-from litellm.proxy._experimental.mcp_server.outbound_credentials.oauth_token_store import (
-    OAuthToken,
-)
-
-if TYPE_CHECKING:
-    from litellm.types.mcp_server.mcp_server_manager import MCPServer
-
-
-class V1PerUserTokenStore:
-    """``OAuthTokenStore`` backed by v1's per-user OAuth egress.
-
-    ``fetch`` looks the server up by id (injected ``server_lookup``) and resolves the token through
-    v1's ``resolve_user_oauth_access_token``, which refreshes an expired token when a refresh_token
-    is stored and re-warms the Redis cache. Returns ``None`` when the user has no usable token (the
-    arm turns that into a challenge); v1's core swallows store errors as a miss, so this never
-    raises ``TokenStoreUnavailable``. The returned ``OAuthToken`` carries only the access token —
-    refresh happens inside the core, not via ``RefreshingTokenStore``.
-    """
-
-    def __init__(self, server_lookup: Callable[[str], MCPServer | None]) -> None:
-        self._server_lookup = server_lookup
-
-    async def fetch(self, user_id: str, server_id: str) -> OAuthToken | None:
-        if not user_id:
-            return None
-        server = self._server_lookup(server_id)
-        if server is None:
-            return None
-
-        from litellm.proxy._experimental.mcp_server.db import (
-            resolve_user_oauth_access_token,
-        )
-
-        access_token = await resolve_user_oauth_access_token(user_id, server)
-        return OAuthToken(access_token=access_token) if access_token else None

tests/test_litellm/proxy/_experimental/mcp_server/outbound_credentials/test_v1_token_store.py

@@ -1,47 +0,0 @@
-"""Tests for the v1-backed per-user OAuth token source (V1PerUserTokenStore)."""
-
-from unittest.mock import AsyncMock, patch
-
-from litellm.proxy._experimental.mcp_server.outbound_credentials.v1_token_store import (
-    V1PerUserTokenStore,
-)
-
-_RESOLVE = "litellm.proxy._experimental.mcp_server.db.resolve_user_oauth_access_token"
-
-
-def _store_for(server: object) -> V1PerUserTokenStore:
-    return V1PerUserTokenStore(server_lookup=lambda _server_id: server)
-
-
-async def test_wraps_the_resolved_access_token():
-    with patch(_RESOLVE, new=AsyncMock(return_value="at-123")):
-        token = await _store_for(object()).fetch("alice", "s")
-    assert token is not None and token.access_token == "at-123"
-
-
-async def test_missing_token_is_none():
-    with patch(_RESOLVE, new=AsyncMock(return_value=None)):
-        assert await _store_for(object()).fetch("alice", "s") is None
-
-
-async def test_empty_user_short_circuits_without_resolving():
-    resolve = AsyncMock(return_value="at")
-    with patch(_RESOLVE, new=resolve):
-        assert await _store_for(object()).fetch("", "s") is None
-    resolve.assert_not_called()
-
-
-async def test_unknown_server_is_none_without_resolving():
-    resolve = AsyncMock(return_value="at")
-    store = V1PerUserTokenStore(server_lookup=lambda _server_id: None)
-    with patch(_RESOLVE, new=resolve):
-        assert await store.fetch("alice", "missing") is None
-    resolve.assert_not_called()
-
-
-async def test_passes_user_and_resolved_server_to_the_core():
-    server = object()
-    resolve = AsyncMock(return_value="at")
-    with patch(_RESOLVE, new=resolve):
-        await _store_for(server).fetch("alice", "srv-1")
-    resolve.assert_awaited_once_with("alice", server)