Include panel member tokens in the chain cost badge

Panel member token usage was tracked but discarded, so the cost badge only
ever showed the worker's tokens — misleading for MoA where the real cost is
roughly rounds x agents. Collect each member's usage and add it to the badge.

Each member fills its own TokenUsage in parallel (Anthropic loop via the
existing memberUsage, CLI via the now-captured CliChatResult return value;
OpenAI members stay null, nachruestbar). RunPanel sums them after the
Task.WhenAll barrier — single-threaded, so no lock or Interlocked needed —
across all MoA rounds and emits a panel_usage SSE event before panel_done.
The frontend adds those tokens onto the worker totals in the done handler so
the badge reflects the full chain cost.

- SseHelper: add TokenUsage.Add()
- AnthropicService.Panel.cs: PanelMemberResult.Usage, accumulate per round
  after the barrier, emit panel_usage; RunPanelMemberViaCli returns usage
- chat.js: _panelUsage state, panel_usage case, add to worker tokens on done,
  reset on stream start
- TODO.md: check off the member-token item

v1 limit: live badge only — FinalizeChain still persists worker tokens, so a
reload shows worker-only cost.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

wwwroot/js/chat.js

@@ -170,6 +170,11 @@ function handleStreamEvent(eventType, data) {
       endPanel(data);
       break;
 
+    case 'panel_usage':
+      // Panel-Member-Tokens merken → im done-Event auf die Worker-Tokens addieren.
+      _panelUsage = data;
+      break;
+
     case 'auto_context':
       addAutoContextBubble(data.context);
       break;
@@ -199,14 +204,18 @@ function handleStreamEvent(eventType, data) {
       if (data.stopReason === 'max_tokens') {
         addWarningBubble('Antwort wurde abgeschnitten (max_tokens erreicht). Bitte frage nach dem Rest.', true);
       }
+      // Panel-Member-Tokens (live gesammelt) auf die Worker-Tokens addieren → Badge = Gesamtkosten.
+      var _pu = _panelUsage;
+      _panelUsage = null;
       _lastDoneChainData = null;
       if (data.model) {
+        _addPanelUsage(data, _pu);
         _lastDoneChainData = data;
       } else if (data.chainId) {
         // Fallback: Chain-Daten vom Server nachladen und Badge direkt rendern
         // (async – _lastDoneChainData wäre im finally schon gelesen)
         apiGetChain(data.chainId).then(chain => {
-          if (chain) addChainMetaBubble(chain, false);
+          if (chain) { _addPanelUsage(chain, _pu); addChainMetaBubble(chain, false); }
         }).catch(() => {});
       }
       setMeta(data.stopReason === 'stopped' ? 'Gestoppt' : 'Bereit');
@@ -235,6 +244,17 @@ function togglePlanMode() {
 
 let isStreaming = false;
 let _lastDoneChainData = null; // Chain-Daten vom letzten done-Event
+let _panelUsage = null; // Panel-Member-Tokens (panel_usage-Event) → werden auf die Worker-Tokens des done-Events addiert
+
+// Addiert die live gesammelten Panel-Member-Tokens auf ein Chain-/done-Objekt, sodass das
+// Token-Badge die Gesamtkosten (Worker + alle Panel-Member aller Runden) zeigt.
+function _addPanelUsage(target, pu) {
+  if (!target || !pu) return;
+  target.inputTokens = (target.inputTokens || 0) + (pu.inputTokens || 0);
+  target.outputTokens = (target.outputTokens || 0) + (pu.outputTokens || 0);
+  target.cacheCreationTokens = (target.cacheCreationTokens || 0) + (pu.cacheCreationTokens || 0);
+  target.cacheReadTokens = (target.cacheReadTokens || 0) + (pu.cacheReadTokens || 0);
+}
 let _currentToolBox = null;   // Aktuell laufende Tool-Box (für Stream-Events)
 let _lastFinishedToolBox = null; // Letzte fertige Tool-Box (für tool_result Zuordnung)
 let _chatAbandoned = false; // true wenn User weg-navigiert während Stream läuft
@@ -320,6 +340,7 @@ async function _runStream(fetchPromise) {
   sendBtn.hidden = true;
   stopBtn.hidden = false;
   isStreaming = true;
+  _panelUsage = null; // frische Chain → alte Panel-Tokens verwerfen
   _abortController = new AbortController();
   // Eine Live-SSE-Antwort rendert ALLEIN. Einen evtl. noch laufenden Recovery-Poll
   // (_streamingPollInterval – gestartet beim Betreten des Chats WAEHREND eine Chain