PerryLink/dsh-fast

Read-only performance diagnostics for DeepSeek Harness: session load (open/restore) timing, spill-hit counts, compaction count and trigger, context-injection volume (AGENTS.md/skills/tool-schema token share), and LLM cache hit rate — surfaced via the /fast command and the fast_report tool, persisted as reconstructable fast/* session events with async sampling off the model path.