feat: add reasoning_effort configuration support for Doubao/GPT-5 models (#947)

* feat: Add reasoning effort configuration support

* Add `reasoning_effort` parameter to model config and agent initialization
* Support reasoning effort levels (minimal/low/medium/high) for Doubao/GPT-5 models
* Add UI controls in input box for reasoning effort selection
* Update doubao-seed-1.8 example config with reasoning effort support

Fixes & Cleanup:
* Ensure UTF-8 encoding for file operations
* Remove unused imports

* fix: set reasoning_effort to None for unsupported models

* fix: unit test error

* Update frontend/src/components/workspace/input-box.tsx

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

frontend/src/core/i18n/locales/en-US.ts

@@ -82,6 +82,15 @@ export const enUS: Translations = {
     ultraMode: "Ultra",
     ultraModeDescription:
       "Pro mode with subagents to divide work; best for complex multi-step tasks",
+    reasoningEffort: "Reasoning Effort",
+    reasoningEffortMinimal: "Minimal",
+    reasoningEffortMinimalDescription: "Retrieval + Direct Output",
+    reasoningEffortLow: "Low",
+    reasoningEffortLowDescription: "Simple Logic Check + Shallow Deduction",
+    reasoningEffortMedium: "Medium",
+    reasoningEffortMediumDescription: "Multi-layer Logic Analysis + Basic Verification",
+    reasoningEffortHigh: "High",
+    reasoningEffortHighDescription: "Full-dimensional Logic Deduction + Multi-path Verification + Backward Check",
     searchModels: "Search models...",
     surpriseMe: "Surprise",
     surpriseMePrompt: "Surprise me",

frontend/src/core/i18n/locales/types.ts

@@ -64,6 +64,15 @@ export interface Translations {
     proModeDescription: string;
     ultraMode: string;
     ultraModeDescription: string;
+    reasoningEffort: string;
+    reasoningEffortMinimal: string;
+    reasoningEffortMinimalDescription: string;
+    reasoningEffortLow: string;
+    reasoningEffortLowDescription: string;
+    reasoningEffortMedium: string;
+    reasoningEffortMediumDescription: string;
+    reasoningEffortHigh: string;
+    reasoningEffortHighDescription: string;
     searchModels: string;
     surpriseMe: string;
     surpriseMePrompt: string;

frontend/src/core/i18n/locales/zh-CN.ts

@@ -80,6 +80,15 @@ export const zhCN: Translations = {
     ultraMode: "Ultra",
     ultraModeDescription:
       "继承自 Pro 模式，可调用子代理分工协作，适合复杂多步骤任务，能力最强",
+    reasoningEffort: "推理深度",
+    reasoningEffortMinimal: "最低",
+    reasoningEffortMinimalDescription: "检索 + 直接输出",
+    reasoningEffortLow: "低",
+    reasoningEffortLowDescription: "简单逻辑校验 + 浅层推演",
+    reasoningEffortMedium: "中",
+    reasoningEffortMediumDescription: "多层逻辑分析 + 基础验证",
+    reasoningEffortHigh: "高",
+    reasoningEffortHighDescription: "全维度逻辑推演 + 多路径验证 + 反推校验",
     searchModels: "搜索模型...",
     surpriseMe: "小惊喜",
     surpriseMePrompt: "给我一个小惊喜吧",

frontend/src/core/models/types.ts

@@ -4,4 +4,5 @@ export interface Model {
   display_name: string;
   description?: string | null;
   supports_thinking?: boolean;
+  supports_reasoning_effort?: boolean;
 }

frontend/src/core/settings/local.ts

@@ -7,6 +7,7 @@ export const DEFAULT_LOCAL_SETTINGS: LocalSettings = {
   context: {
     model_name: undefined,
     mode: undefined,
+    reasoning_effort: undefined,
   },
   layout: {
     sidebar_collapsed: false,
@@ -24,6 +25,7 @@ export interface LocalSettings {
     "thread_id" | "is_plan_mode" | "thinking_enabled" | "subagent_enabled"
   > & {
     mode: "flash" | "thinking" | "pro" | "ultra" | undefined;
+    reasoning_effort?: "minimal" | "low" | "medium" | "high";
   };
   layout: {
     sidebar_collapsed: boolean;

frontend/src/core/threads/types.ts

@@ -18,4 +18,5 @@ export interface AgentThreadContext extends Record<string, unknown> {
   thinking_enabled: boolean;
   is_plan_mode: boolean;
   subagent_enabled: boolean;
+  reasoning_effort?: "minimal" | "low" | "medium" | "high";
 }