feat: adaptive reasoning detection for Codex Chat providers

Auto-detect each Chat-routed Codex provider's reasoning interface from
its name, base URL, and model, then inject the matching thinking
parameter without manual configuration:

- Platform-first inference (OpenRouter, SiliconFlow) overrides model
  rules, since the same model exposes different reasoning controls
  depending on the hosting platform.
- Effort tiers are forwarded only to providers that support them
  (DeepSeek, OpenRouter, and StepFun's step-3.5-flash-2603); on/off-only
  providers (Kimi, GLM, Qwen, MiniMax, MiMo, SiliconFlow) drop the level
  instead of sending a field the upstream rejects.
- OpenRouter uses the native reasoning:{effort} object, clamps max to
  xhigh (its enum has no max), and forwards an explicit effort:"none" so
  reasoning can be turned off.
- StepFun falls back to inference so per-model effort support is honored
  (the static preset would have forced effort on step-3.5-flash too).

Includes the Codex provider-form reasoning controls, i18n strings
(zh/en/ja), and response-side reasoning extraction.

src/types.ts

@@ -137,6 +137,42 @@ export interface ClaudeDesktopModelRoute {
   supports1m?: boolean;
 }
 
+export type CodexChatThinkingParam =
+  | "none"
+  | "thinking"
+  | "enable_thinking"
+  | "reasoning_split";
+
+export type CodexChatEffortParam =
+  | "none"
+  | "reasoning_effort"
+  // OpenRouter 原生归一化对象 reasoning:{effort}（区别于顶层 OpenAI 别名 reasoning_effort）
+  | "reasoning.effort";
+
+export type CodexChatEffortValueMode =
+  | "passthrough"
+  | "low_high"
+  | "deepseek"
+  // OpenRouter effort 枚举 xhigh|high|medium|low|minimal（无 max，max 钳到 xhigh）
+  | "openrouter";
+
+export type CodexChatReasoningOutputFormat =
+  | "auto"
+  | "reasoning_content"
+  | "reasoning"
+  | "reasoning_details"
+  | "think_tags";
+
+export interface CodexChatReasoning {
+  supportsThinking?: boolean;
+  supportsEffort?: boolean;
+  thinkingParam?: CodexChatThinkingParam;
+  effortParam?: CodexChatEffortParam;
+  effortValueMode?: CodexChatEffortValueMode;
+  // 声明性字段：标注上游 reasoning 回传位置。当前提取靠穷举字段，未读取此值（think_tags 尚未接线）。
+  outputFormat?: CodexChatReasoningOutputFormat;
+}
+
 // 供应商元数据（字段名与后端一致，保持 snake_case）
 export interface ProviderMeta {
   // 自定义端点：以 URL 为键，值为端点信息
@@ -181,6 +217,8 @@ export interface ProviderMeta {
   promptCacheKey?: string;
   // Codex OAuth FAST mode: injects service_tier="priority" on ChatGPT Codex requests
   codexFastMode?: boolean;
+  // Codex Responses -> Chat Completions reasoning capability metadata
+  codexChatReasoning?: CodexChatReasoning;
   // 供应商类型（用于识别 Copilot 等特殊供应商）
   providerType?: string;
   // GitHub Copilot 关联账号 ID（旧字段，保留兼容读取）