fix(proxy): satisfy type gates for team-attributed tag spend

DailyTagSpendTransaction.team_id is ReadOnly (LIT012), since nothing writes it
after the transaction is built.

The two payload.get("team_id") reads keep .get rather than indexing and carry
the file's existing reportUnknownMemberType suppression for TypedDict.get. The
caller swallows exceptions at debug level, so indexing would silently drop a
request's tag spend whenever a payload lacked team_id, instead of recording it
as unattributed.

LIT-8516

litellm/proxy/_types.py

@@ -5162,7 +5162,7 @@ class DailyTagSpendTransaction(BaseDailySpendTransaction):
     # "" when the request had no team. Not required: entries queued by a pod running the
     # previous release, or replayed from the Redis buffer across an upgrade, carry no such key,
     # and the upsert reads a missing value as "".
-    team_id: NotRequired[str]
+    team_id: ReadOnly[NotRequired[str]]
 
 
 class DailyAgentSpendTransaction(BaseDailySpendTransaction):

litellm/proxy/db/db_spend_update_writer.py

@@ -918,7 +918,7 @@ class DBSpendUpdateWriter:
             model_group=base.get("model_group"),
             endpoint=base.get("endpoint"),
             mcp_namespaced_tool_name=base.get("mcp_namespaced_tool_name"),
-            team_id=payload.get("team_id") or "",
+            team_id=payload.get("team_id") or "",  # pyright: ignore[reportUnknownMemberType]  # TypedDict.get overloads carry Any defaults
             targets=tuple(
                 DailyBaselineTarget(entity=entity, entity_id=identity)
                 for entity, values in bases
@@ -3035,7 +3035,9 @@ class DBSpendUpdateWriter:
             return
 
         request_tags: Final = daily_spend_entity_ids(payload, "tag")
-        team_id: Final = payload.get("team_id") or ""
+        # .get, not indexing: the caller swallows exceptions at debug level, so a payload without
+        # team_id must still record its tag spend (as unattributed) rather than drop it silently.
+        team_id: Final = payload.get("team_id") or ""  # pyright: ignore[reportUnknownMemberType]  # TypedDict.get overloads carry Any defaults
         for tag in request_tags:
             if tag is None:
                 continue