refactor(provider): switch from full config overwrite to partial key-field merging

Replace the provider switching mechanism for Claude/Codex/Gemini from
full settings_config overwrite to partial key-field replacement, preserving
user's non-provider settings (plugins, MCP, permissions, etc.) across switches.

- Add write_live_partial() with per-app implementations for Claude (JSON env
  merge), Codex (auth replace + TOML partial merge), and Gemini (env merge)
- Add backfill_key_fields() to extract only provider-specific fields when
  saving live config back to provider entries
- Update switch_normal, sync_current_to_live, add, update to use partial merge
- Remove common config snippet feature for Claude/Codex/Gemini (no longer
  needed with partial merging); preserve OMO common config
- Delete 6 frontend files (3 components + 3 hooks), clean up 11 modified files
- Remove backend extract_common_config_* methods, 3 Tauri commands,
  CommonConfigSnippets struct, and related migration code
- Update integration tests to validate key-field-only backfill behavior

src/utils/providerConfigUtils.ts

@@ -3,86 +3,6 @@
 import type { TemplateValueConfig } from "../config/claudeProviderPresets";
 import { normalizeQuotes } from "@/utils/textNormalization";
 
-const isPlainObject = (value: unknown): value is Record<string, any> => {
-  return Object.prototype.toString.call(value) === "[object Object]";
-};
-
-const deepMerge = (
-  target: Record<string, any>,
-  source: Record<string, any>,
-): Record<string, any> => {
-  Object.entries(source).forEach(([key, value]) => {
-    if (isPlainObject(value)) {
-      if (!isPlainObject(target[key])) {
-        target[key] = {};
-      }
-      deepMerge(target[key], value);
-    } else {
-      // 直接覆盖非对象字段（数组/基础类型）
-      target[key] = value;
-    }
-  });
-  return target;
-};
-
-const deepRemove = (
-  target: Record<string, any>,
-  source: Record<string, any>,
-) => {
-  Object.entries(source).forEach(([key, value]) => {
-    if (!(key in target)) return;
-
-    if (isPlainObject(value) && isPlainObject(target[key])) {
-      // 只移除完全匹配的嵌套属性
-      deepRemove(target[key], value);
-      if (Object.keys(target[key]).length === 0) {
-        delete target[key];
-      }
-    } else if (isSubset(target[key], value)) {
-      // 只有当值完全匹配时才删除
-      delete target[key];
-    }
-  });
-};
-
-const isSubset = (target: any, source: any): boolean => {
-  if (isPlainObject(source)) {
-    if (!isPlainObject(target)) return false;
-    return Object.entries(source).every(([key, value]) =>
-      isSubset(target[key], value),
-    );
-  }
-
-  if (Array.isArray(source)) {
-    if (!Array.isArray(target) || target.length !== source.length) return false;
-    return source.every((item, index) => isSubset(target[index], item));
-  }
-
-  return target === source;
-};
-
-// 深拷贝函数
-const deepClone = <T>(obj: T): T => {
-  if (obj === null || typeof obj !== "object") return obj;
-  if (obj instanceof Date) return new Date(obj.getTime()) as T;
-  if (obj instanceof Array) return obj.map((item) => deepClone(item)) as T;
-  if (obj instanceof Object) {
-    const clonedObj = {} as T;
-    for (const key in obj) {
-      if (obj.hasOwnProperty(key)) {
-        clonedObj[key] = deepClone(obj[key]);
-      }
-    }
-    return clonedObj;
-  }
-  return obj;
-};
-
-export interface UpdateCommonConfigResult {
-  updatedConfig: string;
-  error?: string;
-}
-
 // 验证JSON配置格式
 export const validateJsonConfig = (
   value: string,
@@ -102,69 +22,6 @@ export const validateJsonConfig = (
   }
 };
 
-// 将通用配置片段写入/移除 settingsConfig
-export const updateCommonConfigSnippet = (
-  jsonString: string,
-  snippetString: string,
-  enabled: boolean,
-): UpdateCommonConfigResult => {
-  let config: Record<string, any>;
-  try {
-    config = jsonString ? JSON.parse(jsonString) : {};
-  } catch (err) {
-    return {
-      updatedConfig: jsonString,
-      error: "配置 JSON 解析失败，无法写入通用配置",
-    };
-  }
-
-  if (!snippetString.trim()) {
-    return {
-      updatedConfig: JSON.stringify(config, null, 2),
-    };
-  }
-
-  // 使用统一的验证函数
-  const snippetError = validateJsonConfig(snippetString, "通用配置片段");
-  if (snippetError) {
-    return {
-      updatedConfig: JSON.stringify(config, null, 2),
-      error: snippetError,
-    };
-  }
-
-  const snippet = JSON.parse(snippetString) as Record<string, any>;
-
-  if (enabled) {
-    const merged = deepMerge(deepClone(config), snippet);
-    return {
-      updatedConfig: JSON.stringify(merged, null, 2),
-    };
-  }
-
-  const cloned = deepClone(config);
-  deepRemove(cloned, snippet);
-  return {
-    updatedConfig: JSON.stringify(cloned, null, 2),
-  };
-};
-
-// 检查当前配置是否已包含通用配置片段
-export const hasCommonConfigSnippet = (
-  jsonString: string,
-  snippetString: string,
-): boolean => {
-  try {
-    if (!snippetString.trim()) return false;
-    const config = jsonString ? JSON.parse(jsonString) : {};
-    const snippet = JSON.parse(snippetString);
-    if (!isPlainObject(snippet)) return false;
-    return isSubset(config, snippet);
-  } catch (err) {
-    return false;
-  }
-};
-
 // 读取配置中的 API Key（支持 Claude, Codex, Gemini）
 export const getApiKeyFromConfig = (
   jsonString: string,
@@ -329,85 +186,6 @@ export const setApiKeyInConfig = (
   }
 };
 
-// ========== TOML Config Utilities ==========
-
-export interface UpdateTomlCommonConfigResult {
-  updatedConfig: string;
-  error?: string;
-}
-
-// 保存之前的通用配置片段，用于替换操作
-let previousCommonSnippet = "";
-
-// 将通用配置片段写入/移除 TOML 配置
-export const updateTomlCommonConfigSnippet = (
-  tomlString: string,
-  snippetString: string,
-  enabled: boolean,
-): UpdateTomlCommonConfigResult => {
-  if (!snippetString.trim()) {
-    // 如果片段为空，直接返回原始配置
-    return {
-      updatedConfig: tomlString,
-    };
-  }
-
-  if (enabled) {
-    // 添加通用配置
-    // 先移除旧的通用配置（如果有）
-    let updatedConfig = tomlString;
-    if (previousCommonSnippet && tomlString.includes(previousCommonSnippet)) {
-      updatedConfig = tomlString.replace(previousCommonSnippet, "");
-    }
-
-    // 在文件末尾添加新的通用配置
-    // 确保有适当的换行
-    const needsNewline = updatedConfig && !updatedConfig.endsWith("\n");
-    updatedConfig =
-      updatedConfig + (needsNewline ? "\n\n" : "\n") + snippetString;
-
-    // 保存当前通用配置片段
-    previousCommonSnippet = snippetString;
-
-    return {
-      updatedConfig: updatedConfig.trim() + "\n",
-    };
-  } else {
-    // 移除通用配置
-    if (tomlString.includes(snippetString)) {
-      const updatedConfig = tomlString.replace(snippetString, "");
-      // 清理多余的空行
-      const cleaned = updatedConfig.replace(/\n{3,}/g, "\n\n").trim();
-
-      // 清空保存的状态
-      previousCommonSnippet = "";
-
-      return {
-        updatedConfig: cleaned ? cleaned + "\n" : "",
-      };
-    }
-    return {
-      updatedConfig: tomlString,
-    };
-  }
-};
-
-// 检查 TOML 配置是否已包含通用配置片段
-export const hasTomlCommonConfigSnippet = (
-  tomlString: string,
-  snippetString: string,
-): boolean => {
-  if (!snippetString.trim()) return false;
-
-  // 简单检查配置是否包含片段内容
-  // 去除空白字符后比较，避免格式差异影响
-  const normalizeWhitespace = (str: string) => str.replace(/\s+/g, " ").trim();
-
-  return normalizeWhitespace(tomlString).includes(
-    normalizeWhitespace(snippetString),
-  );
-};
-
 // ========== Codex base_url utils ==========
 
 // 从 Codex 的 TOML 配置文本中提取 base_url（支持单/双引号）