[CI] Add Lark notifications for CUDA CI status, runner health, and queue time (#37881)

scripts/ci_monitor/README.md

@@ -1,10 +1,16 @@
 # SGLang CI failure monitoring
 
-Scripts used by [.github/workflows/ci-failure-monitor.yml](../../.github/workflows/ci-failure-monitor.yml): scheduled failure analysis.
+Scripts used by [.github/workflows/ci-failure-monitor.yml](../../.github/workflows/ci-failure-monitor.yml) (scheduled failure analysis) and [.github/workflows/ci-lark-notify.yml](../../.github/workflows/ci-lark-notify.yml) (Lark notifications).
 
 ## Tools
 
 1. **Failures Analyzer** (`ci_failures_analysis.py`): Tracks consecutive failures, identifies flaky jobs, and monitors runner health across PR Test / Nightly workflows (Nvidia, AMD, Intel, XPU, NPU).
+2. **Lark Notifier** (`lark_notify.py`): Posts CUDA CI health cards to a Lark group through an incoming webhook (`LARK_WEBHOOK` secret). Stdlib only. Three subcommands:
+   - `ci-status --run-id N`: one card per finished scheduled run of the Nvidia nightly / weekly / scheduled pr-test. The first attempt lists its failed jobs; a rerun (attempt N > 1) is compared with attempt N-1 of the same run (fixed by rerun / still failing). Triggered by `workflow_run`.
+   - `runner-health --state-file F`: per-pool online / offline counts for the primary CUDA labels (`N-gpu-h100|h200|h20|5090|b200|b300|gb200|gb300|a10`). Posts only on degraded / recovered transitions plus an hourly reminder while degraded; state is carried between runs via `actions/cache`. Needs an admin PAT to list runners.
+   - `queue-digest --hours 6`: per-pool queue time p50 / p90 / max over the window, plus currently queued jobs.
+
+   All subcommands accept `--dry-run` to print the card JSON instead of posting.
 
 ## Installation