Exercise Library/ holds per-exercise reference docs (setup, cues,
mistakes, progressions) with SVG visuals and a Python-rendered motion
pipeline; Workouts/ExerciseFigure renders the bundled *.motion.json
rigs as animated stick figures on the exercise screen. Exercises gain
a warm-up/main-circuit category, timed exercises display hold time via
planSummary, and a completed exercise reopens to a check screen instead
of its timers.
No unit test target existed (testTargets: [] in scheme). Adds a
bundle.unit-test target wired into the Workouts scheme, with a smoke test
that round-trips SplitDocument through IndieSync's DocumentCoder — the
same codec DocumentFileStore uses for every iCloud document.
rzen