feat(code): add XML formatter and validator

[rwv]

Summary

• add a new offline XML formatter and validator tool with pretty-print, minify, import, copy, and download flows
• show XML syntax validation results with line and column details plus inline error context
• register the new tool in the tools registry and add DOM/unit coverage for the package

Testing

• pnpm exec vitest run tools/code/xml-formatter/src
• pnpm exec vitest run --coverage.enabled --coverage.provider=v8 --coverage.reporter=text --coverage.include="tools/code/xml-formatter/src/**/*.{ts,vue}" tools/code/xml-formatter/src
• pnpm exec eslint tools/code/xml-formatter/src registry/tools/src/index.ts registry/tools/src/routes.ts
• pnpm format-check
• pnpm lint-check
• pnpm type-check

Notes

• verified the new tool in a real browser locally with Playwright against http://127.0.0.1:4173/tools/xml-formatter

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	96.34% (🎯 95%)	34292 / 35594
🔵	Statements	96.22% (🎯 94%)	37891 / 39379
🔵	Functions	96.47% (🎯 95%)	12544 / 13002
🔵	Branches	92.74% (🎯 89%)	16934 / 18258

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
registry/tools/src/index.ts	100%	100%	100%	100%
shared/ui/src/components/tool/grid/ToolThing.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/XmlFormatterView.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/index.ts	100%	100%	100%	100%
tools/code/xml-formatter/src/info.ts	100%	100%	100%	100%
tools/code/xml-formatter/src/routes.ts	100%	100%	100%	100%
tools/code/xml-formatter/src/components/WhatIsXmlFormatter.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/components/XmlFormatter.vue	100%	94.44%	100%	100%
tools/code/xml-formatter/src/components/XmlFormatterActions.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/components/XmlFormatterOptions.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/components/XmlFormatterPanels.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/components/XmlFormatterToolbar.vue	100%	100%	100%	100%
tools/code/xml-formatter/src/utils/xml.ts	100%	88.88%	100%	100%

Generated in workflow #1347 for commit 21365ff by the Vitest Coverage Report Action