v0.6.0: 预设供应商 + 供应商账单查询

## 新增

- 15 条主流供应商预设（Kimi Coding / Moonshot / Anthropic /
  DeepSeek / 智谱 GLM / z.ai / 阿里百炼 / MiniMax / StepFun /
  SiliconFlow / Novita / OpenRouter / OpenAI / Google AI Studio /
  火山方舟），通过 PresetPickerModal 一键填表
- 供应商余额/套餐查询（卡片底部 UsageFooter）：余额类
  (DeepSeek / SiliconFlow / OpenRouter / StepFun / Novita) +
  套餐类（Kimi For Coding / 智谱 GLM / MiniMax），5min stale TTL +
  force_refresh + 并发 ≤3
- Rust 端 services/ 模块（balance / coding_plan / usage_types），
  参考 cc-switch（MIT，© Jason Young）实现
- query_provider_usage 命令：Rust 端从 config 加载 key，
  不经 IPC 序列化 API key
- usageKinds 持久化到 SQLite settings（JSON 数组），
  load 时合并回 config，导出 config.toml 时不写
- detect_provider 启发式：旧用户升级后自动获得账单支持
- save-time 校验：未完成供应商（缺 api_key / base_url / 模型）
  保存时弹 confirm 列出原因；新增未提交 back 时静默 drop
- docs/PROPOSAL-presets-and-usage.md（v0.4-draft 实施档）
- docs/VERIFICATION-CHECKLIST.md（70+ 项手动验证清单）

## 修复

- handleDuplicateProvider 的 alias.slice 漏洞：老数据
  非规范 alias 复制不再错位
- handleSelectPreset 不再 auto-save，半成品不会落盘
- handleSwitchProvider 校验取消时自动 refresh 回滚，
  不会出现内存改 / 盘没动的脏态

## 文档

- README / README_EN 致谢段补 cc-switch（预设 + 账单）
- README 已知限制与后续建议段（/reload 上游限制调研结论）
- i18n 补 5 条校验 key + 11 条预设 UI key + 12 条账单 key

详见 docs/PROPOSAL-presets-and-usage.md 与
docs/VERIFICATION-CHECKLIST.md

src/i18n/en.ts

@@ -11,6 +11,12 @@ export const enTranslations: Record<TranslationKey, string> = {
   reloadConfig: "Reload Config",
   openConfigDir: "Open Config Dir",
   unsavedConfirm: "You have unsaved changes. Are you sure you want to reload?",
+  validationNoApiKey: "Missing API key",
+  validationNoBaseUrl: "Missing base URL",
+  validationNoModels: "No models configured",
+  validationBlankModels: "Model entries with empty model id: {aliases}",
+  saveValidationConfirm:
+    "The following providers are not fully configured. Save anyway?\n\n{details}\n\n(Click OK to save to config.toml as-is; click Cancel to keep editing.)",
   providerNotFound: "Provider not found",
   backToList: "Back to list",
   syncToOmp: "Sync to OMP",
@@ -316,4 +322,45 @@ export const enTranslations: Record<TranslationKey, string> = {
   // Sessions — preview
   previewCollapseChars: "Collapse · {n} chars",
   previewExpandChars: "Expand · {n} chars",
+
+  // Provider presets
+  presetPickerTitle: "Choose a provider preset",
+  presetSearchPlaceholder: "Search presets...",
+  presetSortOriginal: "Default",
+  presetSortAlpha: "A-Z",
+  presetNoResults: "No matching presets",
+  presetCustomConfig: "+ Custom configuration",
+  presetFooterHint: "Presets only pre-fill the form; every field stays editable afterwards.",
+  presetCategoryOfficial: "Official",
+  presetCategoryCnOfficial: "China",
+  presetCategoryThirdParty: "Third-party",
+  presetCategoryAggregator: "Aggregator",
+  presetNameAnthropic: "Anthropic",
+  presetNameKimiCoding: "Kimi For Coding",
+  presetNameMoonshot: "Moonshot Platform",
+  presetNameDeepseek: "DeepSeek",
+  presetNameZhipu: "Zhipu GLM",
+  presetNameZai: "z.ai (Zhipu Global)",
+  presetNameBailian: "Alibaba Bailian",
+  presetNameMinimax: "MiniMax",
+  presetNameStepfun: "StepFun",
+  presetNameSiliconflow: "SiliconFlow",
+  presetNameNovita: "Novita AI",
+  presetNameOpenrouter: "OpenRouter",
+  presetNameOpenai: "OpenAI",
+  presetNameGoogleGenai: "Google AI Studio",
+  presetNameVolcengine: "Volcengine Ark",
+
+  // Provider usage
+  usageBalance: "Balance",
+  usageUsed: "used",
+  usageRemaining: "left",
+  usageRefresh: "Refresh",
+  usageRetry: "Retry",
+  usageQueryFailed: "Query failed",
+  usageNetworkError: "Network error",
+  usageInvalidKey: "Invalid API key",
+  usageResetIn: "resets in {time}",
+  usageResetDone: "reset",
+  usageLoading: "Querying…",
 };