Merge branch 'dev' into production

- HeaderClient: track locale prop changes with useRef and call
  window.scrollTo on switch to reliably reset scroll position
- messages/en.json + de.json: replace em dash with comma and remove
  hyphens from Self-Hoster/Full-Stack in hero description

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/__tests__/pre-push-check.test.ts

@@ -268,7 +268,7 @@ describe("Accessibility: images have alt text", () => {
       const content = readFile(file);
       const rel = path.relative(SRC_ROOT, file);
 
-      const imgRegex = /<img\b[^>]*>/g;
+      const imgRegex = /<img\b[^>]*>/gs;
       let match: RegExpExecArray | null;
       while ((match = imgRegex.exec(content)) !== null) {
         const tag = match[0];
@@ -406,19 +406,7 @@ describe("Convention: no raw hex colors in classNames", () => {
 // ═══════════════════════════════════════════════════════════════════════════
 
 describe("Convention: no emoji in app/ source code", () => {
-  function lineContainsEmoji(line: string): boolean {
-    for (let i = 0; i < line.length; i++) {
-      const code = line.codePointAt(i);
-      if (code === undefined) continue;
-      if (code >= 0x1F300 && code <= 0x1FAFF) return true;
-      if (code >= 0x2600 && code <= 0x27BF) return true;
-      if (code >= 0xFE00 && code <= 0xFE0F) return true;
-      if (code === 0x200D) return true;
-      if (code === 0x20E3) return true;
-      if (code > 0xFFFF) i++;
-    }
-    return false;
-  }
+  const EMOJI_REGEX = /[\u{1F300}-\u{1F9FF}\u{2600}-\u{26FF}\u{2700}-\u{27BF}\u{FE00}-\u{FE0F}\u{1F000}-\u{1F02F}\u{1F0A0}-\u{1F0FF}\u{1F100}-\u{1F64F}\u{1F680}-\u{1F6FF}\u{1F700}-\u{1F77F}\u{1F780}-\u{1F7FF}\u{1F800}-\u{1F8FF}\u{1F900}-\u{1F9FF}\u{1FA00}-\u{1FA6F}\u{1FA70}-\u{1FAFF}\u{1FC00}-\u{1FCFF}\u{1FD00}-\u{1FDFF}\u{1FE00}-\u{1FEFF}\u{200D}\u{20E3}\u{E0020}-\u{E007F}]/gu;
 
   const EXCLUDED_DIRS = new Set(["components/admin", "components/modern", "editor"]);
   const EXCLUDED_FILES = new Set([
@@ -445,17 +433,13 @@ describe("Convention: no emoji in app/ source code", () => {
       for (let i = 0; i < lines.length; i++) {
         const line = lines[i];
         if (line.trim().startsWith("//") || line.trim().startsWith("*")) continue;
-        if (lineContainsEmoji(line)) {
-          const emojiChars: string[] = [];
-          for (let j = 0; j < line.length; j++) {
-            const code = line.codePointAt(j);
-            if (code !== undefined && ((code >= 0x1F300 && code <= 0x1FAFF) || (code >= 0x2600 && code <= 0x27BF) || (code >= 0xFE00 && code <= 0xFE0F) || code === 0x200D || code === 0x20E3)) {
-              emojiChars.push(String.fromCodePoint(code));
-              if (code > 0xFFFF) j++;
+        if (EMOJI_REGEX.test(line)) {
+          const emoji = line.match(EMOJI_REGEX);
+          if (emoji) {
+            violations.push(`${rel}:${i + 1} — found emoji: ${emoji.join(", ")}`);
           }
         }
-          violations.push(`${rel}:${i + 1} — found emoji: ${emojiChars.join(", ")}`);
-        }
+        EMOJI_REGEX.lastIndex = 0;
       }
     }