Bug description

The Astro compiler incorrectly handles Unicode "smart" quotation marks („" — U+201E/U+201D, and "" — U+201C/U+201D) when they appear inside HTML attribute values in the template section of .astro files.

When a template attribute like answerBox="text with „quoted words" inside" is compiled, the right double quotation mark " (U+201D) is interpreted as closing the attribute value — even though it's a different character from " (U+0022). This causes the remaining text to be parsed as separate HTML attributes, producing invalid compiled JavaScript like {".":true,"next":true,"word":true,...}.

Expected behavior

Unicode quotation marks („", "", «») inside "" attribute values should be treated as regular text content, not as attribute delimiters. Only ASCII " (U+0022) should close an attribute opened with ASCII ".

Reproduction

---
// No frontmatter needed
---

<SomeComponent
  text="This has „Polish quotes" inside"
/>

The compiled output incorrectly splits "Polish quotes" as if " (U+201D) closes the attribute, producing broken JS.

Workaround

Use JSX expression syntax instead of HTML attribute syntax:

<SomeComponent
  text={'This has „Polish quotes" inside'}
/>

Or avoid Unicode quotation marks entirely in attribute values.

Impact

This is particularly problematic for multilingual sites (Polish, German, Czech, Slovak use „" quotation marks; French uses «»; Ukrainian uses «»). Any i18n content with native quotation marks in component props will break the build silently.

Environment

• Astro: 6.1.3
• @astrojs/cloudflare: 13.1.7
• @astrojs/compiler: (bundled with astro)
• esbuild: 0.27.4
• Node: 25.2.1
• OS: macOS