Make the selection highlight read as glossy candy without new art and
without disturbing the idle-rest invariant. board_view's render_selection
layers a soft outward glow (two concentric stroked rings — the renderer has
no blur), a warm wash, a bright rim doubled by a thin inner highlight for a
glassy edge, and a wet sheen that rides the selected gem's live pose. Every
layer is a rect/overlay (issue 0002 forbids a draw-time gem-texture tint).
The gloss is selection-only: render_selection runs solely when a cell is
selected, so the resting board (no selection) is byte-identical to before
and the t==0 idle pose stays exactly the static sprite (locked by
tests/gem_pose). The selection-pop motion still comes from gem_anim; no
board / score / move state changes and input stays gated by BoardAnim.active.
Updated goldens/p6_select.png; README documents the P11.3 selection gloss
and its reproduce commands (reusing the P6.3 M3TE_SELECT + M3TE_ANIM_TIME
hooks).
cd8667d170
