Feature: Per-character sound font mapping for events (shared sound sequences)

Summary:\n- Introduce per-character sound font: a table of indices into a shared pool of sound sequences (samples) for events like jump, stop/reverse, attack, hurt, long fall/land, KO, select, etc.\n\nDesign notes:\n- Sounds (sequences) are shared globally to conserve ROM; characters reference them by index.\n- Each character gets a fixed-size block of slots (TBD size) mapping event->soundIndex.\n- At runtime, event dispatcher plays the referenced sequence.\n- Example: 'Squish' sequence might be used for Bernie’s hurt and land-from-fall events.\n\nOpen questions:\n- Reasonable number of slots per character (budget vs. variety): propose 8–16 slots.\n- Sequence encoding size budget per unique sound; expected total ROM impact.\n- Tooling: pipeline for authoring sequences and validating slot references.\n\nAcceptance criteria:\n- Data structures defined (shared sequences; per-character font table).\n- Event hooks use character font to select sequence.\n- Build and tools validate indices; fallback when slot unset.\n