feat: improve request pricing, model diagnostics, and client discovery

- Align response model handling with CPA-Manager-Plus and flag routing mismatches
- Add per-request costs and CSV export; fix mixed-context cost aggregation
- Display API-reported access types and move providers next to timestamps
- Use white table backgrounds and simplify cost and status displays
- Expand client discovery paths, validate executables, and prioritize installed clients
- Add model, pricing, client discovery, and UI regression tests

src/services/usageModel.ts

@@ -0,0 +1,12 @@
+/** Match CPA-Manager-Plus request monitoring: compare the response with the routed model. */
+export function usageModelDetails(model: string, alias = '', response = '') {
+  const resolved = model.trim();
+  const requested = alias.trim() || resolved || '—';
+  const responseModel = response.trim();
+  return {
+    requested, resolved, response: responseModel,
+    showResolved: Boolean(resolved && resolved !== requested),
+    mismatch: Boolean(responseModel && resolved && responseModel !== resolved),
+    showResponseInTooltip: Boolean(responseModel && (!resolved || responseModel !== resolved)),
+  };
+}

src/services/usageProvider.ts

@@ -0,0 +1,18 @@
+/** Usage API values describe the route, not the brand implied by a model name. */
+export function usageProviderDetails(provider: string, authType = '') {
+  const rawProvider = provider.trim();
+  const rawAuthType = authType.trim();
+  const labels: Record<string, string> = {
+    codex: 'Codex', claude: 'Claude', gemini: 'Gemini', aistudio: 'AI Studio',
+    antigravity: 'Antigravity', openai: 'OpenAI', 'openai-compatibility': 'OpenAI Compatible',
+    vertex: 'Vertex AI', 'vertex-ai': 'Vertex AI', xai: 'xAI', grok: 'Grok',
+  };
+  return {
+    name: labels[rawProvider.toLowerCase()] ?? (rawProvider || '—'),
+    access: rawAuthType.toLowerCase() === 'apikey' ? 'API'
+      : rawAuthType.toLowerCase() === 'oauth' ? 'OAuth'
+        : rawAuthType && rawAuthType.toLowerCase() !== 'unknown' ? rawAuthType : '',
+    rawProvider,
+    rawAuthType,
+  };
+}