feat(icons): split built-in sprite into per-icon SVG sources and add ticket icon

Move the 114 built-in sprite icons out of assets/js/runtime/svg-icon.js into
assets/icons/sprite/{key}.svg and generate svg-icon.js with
tools/build-svg-sprite.mjs. Add ticket-color and use it for the user center
ticket entry. Update sidebar contract tests for the creator card labels.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/icons/sprite/extra-points.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1024 1024"><path d="M949.79 815.69L551.71 126.21a45.27 45.27 0 0 0-78.42 0L75.21 815.69c-17.42 30.18 4.36 67.92 39.22 67.92h796.14c34.86 0 56.64-37.74 39.22-67.92zM185 797.61l327.5-567.32L840 797.61z"></path></svg>