Fix Aliyun FC sandbox tool session payload

[dragonforce2010]

Summary

• pass session_id through cloud runtime tool payloads for veFaaS and Aliyun FC tools
• cover Aliyun FC sandbox tool requests with a contract assertion
• update stable veFaaS public base fallback to the current stable gateway

Verification

• rtk bun run typecheck
• rtk python3 -m py_compile infra/vefaas/deploy_vefaas_application.py
• rtk zsh -lc 'set -a; source /Users/bytedance/workspace/open-maple/.env; set +a; bun run test:aliyun-provider-orchestration'\n- rtk git diff --check\n\n## Online E2E proof\n- stable URL: https://sd8t0ln1jtbcjjsjsmb80.apigateway-cn-beijing.volceapi.com\n- run id: aliyunfc-sbx-mqqw404z\n- session: sess_6J6KfDRKGm\n- proof JSON: /private/tmp/openmaple-aliyun-proof/aliyunfc-sbx-mqqw404z-verified.json\n- screenshot: /Users/bytedance/.codex/worktrees/b0ac/open-maple/aliyun-fc-sandbox-e2e-proof.png\n- assertions: agent_runtime.type=aliyun_fc, sandbox_runtime.type=aliyun_fc_sandbox, final runtime=aliyun_fc_agent_loop, list_files/write_file/bash completed\n\n## Cleanup\n- deleted maple-agt-sbx-e2e-mqqw404z, status recheck FunctionNotFound 404\n- deleted maple-sbx-e2e-mqqw404z, status recheck FunctionNotFound 404