dsh-usage-insights: Local read-only usage panel for DeepSeek Harness

dsh-usage-insights is a local, read-only usage dashboard plugin for DeepSeek Harness, designed to address the difficulty developers face in directly verifying Token usage, requests, Agent activities, and performance data scattered across session events. This plugin does not generate new model calls or display financial costs; it only reads local session data from DSH. It provides filterable, exportable, and verifiable statistics under "Settings > Work Activity." Its core features include: filtering by IANA timezone natural day, workspace, provider, and model (the tool dimension does not accept combinations of the latter two); separately displaying cached and non-cached Tokens, request counts, and performance metrics (such as TTFT and output speed); and providing daily trend charts and multi-dimensional paginated details with support for search, sorting, and UTF-8 CSV export. The current version is 0.