dsh-plugin-session-token-stats: Transform DSH session logs into a Token usage dashboard

DSH Web profile only writes session logs to disk and does not aggregate token consumption. This plugin reads real logs to generate total volume, cache hit rate, monthly usage, daily timelines, and session-level details, accompanied by CPU/memory monitoring. It counts only tokens and deliberately omits cost information. This section introduces its display content, counting methodology, deduplication rules, installation command, Host routing, self-check method, and precautions.