Feat/pricing config enhancement (#781)

* feat(db): add pricing config fields to proxy_config table

- Add default_cost_multiplier field per app type
- Add pricing_model_source field (request/response)
- Add request_model field to proxy_request_logs table
- Implement schema migration v5

* feat(api): add pricing config commands and provider meta fields

- Add get/set commands for default cost multiplier
- Add get/set commands for pricing model source
- Extend ProviderMeta with cost_multiplier and pricing_model_source
- Register new commands in Tauri invoke handler

* fix(proxy): apply cost multiplier to total cost only

- Move multiplier calculation from per-item to total cost
- Add resolve_pricing_config for provider-level override
- Include request_model and cost_multiplier in usage logs
- Return new fields in get_request_logs API

* feat(ui): add pricing config UI and usage log enhancements

- Add pricing config section to provider advanced settings
- Refactor PricingConfigPanel to compact table layout
- Display all three apps (Claude/Codex/Gemini) in one view
- Add multiplier column and request model display to logs
- Add frontend API wrappers for pricing config

* feat(i18n): add pricing config translations

- Add zh/en/ja translations for pricing defaults config
- Add translations for multiplier, requestModel, responseModel
- Add provider pricing config translations

* fix(pricing): align backfill cost calculation with real-time logic

- Fix backfill to deduct cache_read_tokens from input (avoid double billing)
- Apply multiplier only to total cost, not to each item
- Add multiplier display in request detail panel with i18n support
- Use AppError::localized for backend error messages
- Fix init_proxy_config_rows to use per-app default values
- Fix silent failure in set_default_cost_multiplier/set_pricing_model_source
- Add clippy allow annotation for test mutex across await

* style: format code with cargo fmt and prettier

* fix(tests): correct error type assertions in proxy DAO tests

The tests expected AppError::InvalidInput but the DAO functions use
AppError::localized() which returns AppError::Localized variant.
Updated assertions to match the correct error type with key validation.

---------

Co-authored-by: Jason <farion1231@gmail.com>

src/lib/api/proxy.ts

@@ -92,4 +92,29 @@ export const proxyApi = {
   async updateProxyConfigForApp(config: AppProxyConfig): Promise<void> {
     return invoke("update_proxy_config_for_app", { config });
   },
+
+  // ========== 计费默认配置 API ==========
+
+  // 获取默认成本倍率
+  async getDefaultCostMultiplier(appType: string): Promise<string> {
+    return invoke("get_default_cost_multiplier", { appType });
+  },
+
+  // 设置默认成本倍率
+  async setDefaultCostMultiplier(
+    appType: string,
+    value: string,
+  ): Promise<void> {
+    return invoke("set_default_cost_multiplier", { appType, value });
+  },
+
+  // 获取计费模式来源
+  async getPricingModelSource(appType: string): Promise<string> {
+    return invoke("get_pricing_model_source", { appType });
+  },
+
+  // 设置计费模式来源
+  async setPricingModelSource(appType: string, value: string): Promise<void> {
+    return invoke("set_pricing_model_source", { appType, value });
+  },
 };