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/gitee.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1024 1024"><path d="M978.5 409.6H455.1c-25.1 0-45.5 20.3-45.5 45.5v113.7c0 25.1 20.3 45.5 45.5 45.5h318.6c25.1 0 45.5 20.4 45.5 45.5v22.6c0 75.4-61.2 136.5-136.5 136.5H250.3c-25.1 0-45.5-20.4-45.5-45.5V341.2c0-75.5 61.2-136.5 136.5-136.5h637c25.1 0 45.5-20.3 45.5-45.5l0.1-113.6c0-25.1-20.3-45.5-45.5-45.5H341.3C152.9 0 0 152.9 0 341.3v637.2c0 25.1 20.4 45.5 45.5 45.5h671.3c169.6 0 307.2-137.5 307.2-307.2V455.1c0-25.1-20.4-45.5-45.5-45.5z"></path></svg>