STATE-WP-0069 T04: Sunset headers and POST /progress body metering

Add Sunset to legacy compat responses (Jun 2027 planning horizon).
Meter POST /progress/ bodies that use workstream_id; wire hub-core body
hook. Consolidate workstreams deprecation headers via legacy_compat.

api/routers/progress.py

@@ -1,14 +1,16 @@
+from typing import Any
+
 from fastapi import Request, Response
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from api.database import get_session
 from api.models.progress_event import ProgressEvent
 from api.schemas.progress_event import ProgressEventCreate, ProgressEventRead
-from api.services.legacy_compat import meter_legacy_query_param
+from api.services.legacy_compat import meter_legacy_body_field, meter_legacy_query_param
 from hub_core.routers.progress import create_progress_router
 
 
-async def _meter_progress_workstream_id(
+async def _meter_progress_workstream_id_query(
     session: AsyncSession,
     request: Request,
     response: Response,
@@ -23,12 +25,34 @@ async def _meter_progress_workstream_id(
     )
 
 
+async def _meter_progress_workstream_id_body(
+    session: AsyncSession,
+    request: Request,
+    response: Response,
+) -> None:
+    await meter_legacy_body_field(
+        session=session,
+        request=request,
+        response=response,
+        method="POST",
+        route="/progress/",
+        field="workstream_id",
+        replacement_ref="POST /progress/ with workplan_id",
+    )
+
+
+def _progress_body_uses_legacy_workstream_id(body: Any) -> bool:
+    return bool(getattr(body, "used_legacy_workstream_id", False))
+
+
 router = create_progress_router(
     get_session,
     progress_model=ProgressEvent,
     progress_create_schema=ProgressEventCreate,
     progress_read_schema=ProgressEventRead,
-    meter_legacy_workstream_id=_meter_progress_workstream_id,
+    meter_legacy_workstream_id=_meter_progress_workstream_id_query,
+    progress_body_uses_legacy_workstream_id=_progress_body_uses_legacy_workstream_id,
+    meter_legacy_workstream_id_body=_meter_progress_workstream_id_body,
 )
 
 __all__ = ["router"]

api/routers/workstreams.py

@@ -23,6 +23,7 @@ from api.schemas.workplan import (
     WorkplanUpdate,
 )
 from api.services.lifecycle import transition_workplan_status
+from api.services.legacy_compat import mark_legacy_response
 from api.services.legacy_meter import (
     LegacyUsageIdentity,
     identity_from_request,
@@ -86,14 +87,6 @@ def _legacy_key(method: str, route: str) -> str:
     return f"rest_api:{method} {route}"
 
 
-def _mark_legacy_response(response: Response | None, replacement_ref: str) -> None:
-    if response is None:
-        return
-    response.headers["Deprecation"] = "true"
-    response.headers["X-StateHub-Replacement"] = replacement_ref
-    response.headers.append("Link", f"<{replacement_ref}>; rel=\"successor-version\"")
-
-
 async def _meter_legacy_route(
     *,
     session: AsyncSession,
@@ -102,7 +95,7 @@ async def _meter_legacy_route(
     interface_key: str,
     replacement_ref: str,
 ) -> None:
-    _mark_legacy_response(response, replacement_ref)
+    mark_legacy_response(response, replacement_ref)
     try:
         await record_legacy_usage(
             session,