fix(rsc): prevent catastrophic backtracking in directive regex

The regular expression used to preserve "use client" and "use server" directives was flawed and could backtrack into single-line comments that contained string literal characters. This resulted in the virtual CSS import being injected inside comments or invalid positions, causing syntax errors in files with URL queries like `?url` or `?raw` (e.g. static-assets tests).

This fix changes the comment and string literal matching to prevent backtracking and ensures we only match true top-level string directives.

Author: colinaaa

src/index.ts

@@ -181,7 +181,7 @@ export const pluginTailwindCSS = (
         const importStr = `import "${pathToFileURL(VIRTUAL_UTILITIES_ID)}?${params.toString()}";\n`;
 
         const match = code.match(
-          /^(?:[\s]*|(?:\/\*[\s\S]*?\*\/)|(?:\/\/[^\n]*\n?))*(?:(?:(?:"[^"]*"|'[^']*')[ \t]*;?)(?:[ \t]*\/\/[^\n]*\n?|[ \t]*\/\*[\s\S]*?\*\/|[\s]*))+/,
+          /^(?:[\s]*|(?:\/\*[\s\S]*?\*\/)|(?:\/\/[^\n]*(?:\n|$)))*(?:(?:(?:"[^"\n\r]*"|'[^'\n\r]*')[ \t]*;?)(?:[\s]*|(?:\/\*[\s\S]*?\*\/)|(?:\/\/[^\n]*(?:\n|$)))*)+/,
         );
 
         if (match) {