feat(release): bound durable run retention

tools/release/server/app.py

@@ -249,9 +249,11 @@ def create_app(
         return to_jsonable(release_plan)
 
     @app.get("/api/release-runs")
-    def release_runs(limit: int = 20) -> dict[str, object]:
+    def release_runs(
+        limit: int = 20, cursor: str | None = None
+    ) -> dict[str, object]:
         try:
-            return {"runs": app.state.release_runs.list(limit=limit)}
+            return app.state.release_runs.list_page(limit=limit, cursor=cursor)
         except (ReleaseRunConflict, ReleaseRunCorrupt) as exc:
             raise HTTPException(status_code=409, detail=str(exc)) from exc