fix(report): address CodeRabbit review — pricing match, sidechain filter, UX guards

- getPricing: use tokenized order-insensitive matching so Claude 3 era
  models (e.g. "claude-3-opus-20240229") correctly match pricing key "opus-3"
- sessionAnalyzer: skip isSidechain messages in parentCost loop to prevent
  double-counting with processSubagentCost
- CostSection: disable row expansion when token stats are missing
- tabSlice: guard against undefined sessionId/projectId in openSessionReport

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

src/renderer/components/report/sections/CostSection.tsx

@@ -182,17 +182,17 @@ export const CostSection = ({
           <tbody>
             {modelEntries.map(([model, cost]) => {
               const stats = tokensByModel[model];
-              const isExpanded = expandedModel === model;
+              const isExpanded = expandedModel === model && !!stats;
               const pricing = getPricing(model);
               return (
                 <Fragment key={model}>
                   <tr
-                    className="border-border/50 hover:bg-surface-raised/50 cursor-pointer border-b"
-                    onClick={() => setExpandedModel(isExpanded ? null : model)}
+                    className={`border-border/50 border-b ${stats ? 'hover:bg-surface-raised/50 cursor-pointer' : ''}`}
+                    onClick={() => stats && setExpandedModel(isExpanded ? null : model)}
                   >
                     <td className="py-1.5 pr-4 text-text">
                       <span className="mr-1.5 inline-block w-3 text-text-muted">
-                        {isExpanded ? '\u25BC' : '\u25B6'}
+                        {stats ? (isExpanded ? '\u25BC' : '\u25B6') : ''}
                       </span>
                       {model}
                     </td>

src/renderer/store/slices/tabSlice.ts

@@ -387,6 +387,7 @@ export const createTabSlice: StateCreator<AppState, [], [], TabSlice> = (set, ge
     const allTabs = getAllTabs(state.paneLayout);
     const sourceTab = allTabs.find((t) => t.id === sourceTabId);
     if (sourceTab?.type !== 'session') return;
+    if (!sourceTab.sessionId || !sourceTab.projectId) return;
 
     const tabData = state.tabSessionData[sourceTabId];
     const firstMsg = tabData?.sessionDetail?.session.firstMessage;

src/renderer/utils/sessionAnalyzer.ts

@@ -104,9 +104,10 @@ const DEFAULT_PRICING: ModelPricing = {
 };
 
 export function getPricing(modelName: string): ModelPricing {
-  const name = modelName.toLowerCase();
+  const nameTokens: string[] = modelName.toLowerCase().match(/[a-z0-9]+/g) ?? [];
   for (const [key, pricing] of Object.entries(MODEL_PRICING)) {
-    if (name.includes(key)) return pricing;
+    const keyTokens: string[] = key.match(/[a-z0-9]+/g) ?? [];
+    if (keyTokens.every((t) => nameTokens.includes(t))) return pricing;
   }
   return DEFAULT_PRICING;
 }
@@ -454,7 +455,9 @@ export function analyzeSession(detail: SessionDetail): SessionReport {
     }
 
     // --- Token usage, cache economics, and cost ---
-    if (m.usage && m.model) {
+    // Skip sidechain messages to avoid double-counting (subagent costs are
+    // accounted for separately via processSubagentCost).
+    if (m.usage && m.model && !m.isSidechain) {
       const model = m.model;
       const u = m.usage;
       const inpTok = u.input_tokens ?? 0;