feat: Chain-Meta Anzeige-Einstellung + Darstellung verbessern

- Settings: 'Chain-Info' Dropdown (Immer/Manchmal/Nie), Default 'Manchmal'
- Manchmal-Regeln: In+Out >= 10k Tokens, >= 25 Iterationen, >= 90s Dauer
- Model-Name: claude-opus-4-6 → Opus 4.6, Unbekanntes → 'Unbekannt'
- Tokens: In/Out zu einem Badge zusammengeführt
- Cache: Read/Write zu einem Badge zusammengeführt
- Iterations → Iterationen

wwwroot/js/chat.js

@@ -1,13 +1,30 @@
 // ── Helpers ──
 
+function _prettyModelName(model) {
+  if (!model) return '?';
+  // claude-sonnet-4-20250514 → Sonnet 4
+  // claude-opus-4-6 → Opus 4.6
+  // claude-haiku-3-5 → Haiku 3.5
+  const m = model.match(/claude-(\w+)-(\d+)(?:-(\d+))?/);
+  if (m) {
+    const family = m[1].charAt(0).toUpperCase() + m[1].slice(1);
+    const major = m[2];
+    const minor = m[3];
+    // minor > 20000000 ist ein Datums-Suffix, kein Minor-Version
+    if (minor && minor.length <= 2) return family + ' ' + major + '.' + minor;
+    return family + ' ' + major;
+  }
+  return 'Unbekannt';
+}
+
 function buildMetaBadges(d) {
   const badges = [];
-  badges.push(d.model || '?');
-  badges.push('In: ' + (d.inputTokens || 0));
-  badges.push('Out: ' + (d.outputTokens || 0));
-  if (d.cacheCreationTokens > 0) badges.push('Cache-Write: ' + d.cacheCreationTokens);
-  if (d.cacheReadTokens > 0) badges.push('Cache-Read: ' + d.cacheReadTokens);
-  if ((d.iterations || 0) > 1) badges.push('Iterations: ' + d.iterations);
+  badges.push(_prettyModelName(d.model));
+  badges.push('Tokens: ' + (d.inputTokens || 0) + ' / ' + (d.outputTokens || 0));
+  if (d.cacheCreationTokens > 0 || d.cacheReadTokens > 0) {
+    badges.push('Cache: ' + (d.cacheReadTokens || 0) + ' / ' + (d.cacheCreationTokens || 0));
+  }
+  if ((d.iterations || 0) > 1) badges.push('Iterationen: ' + d.iterations);
   if (d.durationMs) badges.push((d.durationMs / 1000).toFixed(1) + 's');
   if (d.stopReason && d.stopReason !== 'end_turn' && d.stopReason !== 'tool_use') badges.push('Stop: ' + d.stopReason);
   return badges;
@@ -17,6 +34,7 @@ function addChainMetaBubble(d, streamed) {
   if (!d || !d.model) return;
   // Chain noch nicht finalisiert (läuft noch) → nicht anzeigen
   if (!d.inputTokens && !d.outputTokens && !d.durationMs) return;
+  if (!isChainMetaVisible(d)) return;
   const badges = buildMetaBadges(d);
   const div = document.createElement('div');
   div.className = 'chain-meta';