hourly LLM concision sampler for agent-to-agent messages

Elazar 2026-07-13: add an hourly haiku/sonnet sampler reading ~10 RANDOM agent-to-agent message bodies (random, not biggest/most-frequent) and coaching CONCISION — flowery language, long explanations, performance-layer padding, 3-paragraphs-for-a-5-line-point. Coach via before/after rewrite (coder-mars-cc verbose done: -> tight 5-line done: is the target shape). Size alone is not the signal; padding-relative-to-content is. Adds to the daily v1.4 wrapper sweep. PM's lane (extends llmmsg-kpi-coach.sh + rules file + a new hourly timer). No hub change.