Make Eval SDK sheet operation waits websocket-first

[hasaan21]

Summary

Make Eval SDK sheet operation waits websocket-first so CLI cell_progress tracks the dashboard 1:1 via SMART_TABLE_EXECUTION_STATUS_UPDATE, with REST polling as fallback.

Changes

• Add evaluations/live_progress.py Centrifugo listener for sheet execution-status updates (filter by operation execution_ids)
• Wire wait_for_sheet_operations / await_for_sheet_operations to WS-first progress; sync path runs async under the hood
• Keep light REST safety poll; fall back to REST if WS token/connect/subscribe fails
• Support optional statuses on wait helpers (None = STALE-only API default; [] = force all cells)
• Add SDK tests for matching IDs, ignored foreign IDs, and REST fallback

Test Plan

• Tested locally
• Added/updated tests
• Verified in staging
• poetry run pytest tests/test_eval_polling.py
• Manual: sample-promptlayer-python/recalc_traces_download.py with statuses=[] → live cells N/M aligned with UI

Checklist

• Code follows project conventions
• No any types in TypeScript (frontend)
• Tests pass locally
• Documentation updated if needed
• Update promptlayer-helm if you add a new envvar (env/ is tied to Cloud Run only and will be removed soon)