Pick any exercise from the full library while a workout is running, not
just the ones in its split. The new exercise's plan is seeded from the
most recent log of that exercise, else the library's authored Defaults
line, else a plain 3x10. Adds a searchable two-section picker sheet and
a **Defaults:** bullet to all 47 library reference pages.
Claude-Session: https://claude.ai/code/session_01HJDQQDA9QdP8zByg43H5v3
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.