The restart button (BoardView.do_restart) reseeded the model and dropped
selection/drag/anim/FX, but left GemMotion.land_at carrying the prior move's
landing stamps. A restart fired right after a terminal cascade therefore
replayed that move's squash-bounce on the freshly seeded board instead of
showing a clean resting pose.
Factor the landing reset into GemMotion.reset_landings (init now delegates to
it) and call it from do_restart, so a restart returns every cell to its
resting idle pose. The idle clock keeps running, so the always-on idle simply
resumes from rest.
Regression: tests/gem_pose.sx section 7 stamps a cell mid-squash, asserts it
is squashing, then asserts reset_landings returns every cell to rest while
leaving the clock untouched. Fails on the pre-fix (no-op reset) behaviour,
passes after. Gate green: ios-sim build + 18/18 logic tests.
New gem_anim.sx adds a purely-visual per-gem pose set driven by a single
animation clock: a calm always-on idle breath (scale-pulse + bob, per-gem
phase, ramped in from rest), a selection pop, a landing squash-bounce, and
a clear pop. BoardView draws every settled gem through gem_pose_at /
gem_pose_frame; the move timeline (P6.1) and FX (P6.2) are untouched and the
input-lock semantics are unchanged (idle never locks input).
Determinism: the idle is always-on, so main reads M3TE_ANIM_TIME=<seconds>
to freeze the clock at a chosen phase (t==0 == the resting board, so the
pre-P6.3 goldens reproduce) and M3TE_SELECT=<cellIndex> to force a selection
for capture. tests/gem_pose.sx locks the t==0-rest invariant and the reaction
envelopes headlessly (fails if the idle ramp is dropped).
Goldens (deterministic capture): p6_idle_t0 (resting), p6_idle_mid (pinned
mid-breath), p6_select (selection pop on cell 3,3). Purely visual: no change
to model/score/moves/hit-testing.
