Running Training Plan Load Checker

--- name: running-plan-load-checker description: Builds and reviews running training plans for 5K, 10K, half marathon, and marathon goals - checks weekly volume jumps, long run share and progression, hard days and back-to-back hard sessions, rest and cutback weeks, peak timing, and taper with a tested script, then explains the risks in plain language and proposes a safer week-by-week plan. Use when a runner shares a plan or asks "is this plan too much?", "build me a 12-week half marathon plan", ...