feat(park-company): 园区企业→成员 + 企业算力(折扣%/配额，只增不减) 后端

- 迁移0015：park_companies 加 compute_discount/compute_quota/compute_quota_used/engine_group/owner_user_id；users 加 park_company_id(成员归属一家企业)
- tenants.py：company_members/get/add/remove(写 users.park_company_id)、available_members(候选)、set_company_compute(折扣%/配额 单调非降，越界 ValueError)、sync_company_engine(引擎组倍率同步,best-effort)
- park/routers.py：carrier 端点 company-members GET/POST/DELETE、company-pool、companies/{cid}/compute(monotonic+引擎同步)；鉴权 _carrier_user+_my_park 隔离本园区
- compute_client.py：set_user_group_by_username、set_group_group_ratio(组倍率=1-discount%)、grant_user_quota_by_username(解析引擎id后 add_quota)
- rbac_admin.py：平台兜底 GET /park/tenants/{tid}/companies、PUT .../companies/{cid}/compute(monotonic+audit)
- _user_to_dict 暴露 park_company_id
- 单调校验服务端强判：折扣降/配额负增 → 400

Co-Authored-By: Claude <noreply@anthropic.com>

app/api/routers/rbac_admin.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from fastapi import APIRouter, Depends, HTTPException, Request
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 from ..dependencies import get_db
 from ..schemas.admin import SetUserRoleRequest, SetUserStatusRequest, UserClassificationRequest
@@ -456,3 +456,49 @@ async def admin_park_unbind_device(
     await write_audit(db, action="park.unbind_screen", resource="park_screen",
         resource_id=device_id, detail=f"from tid={dev.get('tenant_id')}", user=actor, request=request)
     return {"ok": True}
+
+
+class AdminCompanyComputeBody(BaseModel):
+    discount: int | None = Field(default=None, ge=0, le=100)
+    quota_add: int = Field(default=0, ge=0)
+
+
+@router.get("/park/tenants/{tid}/companies", summary="园区企业列表（含成员数/算力，平台）")
+async def admin_park_tenant_companies(
+    tid: str,
+    db: Database = Depends(get_db),
+    _role: dict = Depends(require_roles("operator")),
+    _perm: dict = Depends(require_permission("menu:admin_user_mgmt")),
+):
+    from app.park import tenants as tnt
+    return {"items": await tnt.list_companies(tid)}
+
+
+@router.put("/park/tenants/{tid}/companies/{cid}/compute", summary="设置企业算力（只增不减，平台兜底）")
+async def admin_park_tenant_company_compute(
+    tid: str,
+    cid: str,
+    body: AdminCompanyComputeBody,
+    request: Request,
+    db: Database = Depends(get_db),
+    actor: dict = Depends(require_permission("action:user.manage")),
+):
+    from app.park import tenants as tnt
+    c = await tnt.get_company(cid)
+    if c is None or c.get("tenant_id") != tid:
+        raise HTTPException(status_code=404, detail="企业不存在")
+    try:
+        updated = await tnt.set_company_compute(cid, discount=body.discount, quota_add=body.quota_add)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    await tnt.sync_company_engine(cid)
+    if body.quota_add > 0:
+        from ..services import compute_client
+        for m in await tnt.company_members(cid):
+            try:
+                await compute_client.grant_user_quota_by_username(m["username"], body.quota_add)
+            except Exception:  # noqa: BLE001
+                continue
+    await write_audit(db, action="park.company_compute", resource="park_company",
+        resource_id=cid, detail=f"discount={body.discount} quota_add={body.quota_add}", user=actor, request=request)
+    return {"ok": True, "company": updated, "quota_add": body.quota_add}