feat: add real-time TOML validation for Codex config

- Add smol-toml dependency for client-side TOML parsing
- Create useCodexTomlValidation hook with 500ms debounce
- Display validation errors below config.toml textarea
- Trigger validation on onChange for immediate user feedback
- Backend validation remains as fallback for data integrity

src/components/providers/forms/hooks/index.ts

@@ -10,3 +10,4 @@ export { useTemplateValues } from "./useTemplateValues";
 export { useCommonConfigSnippet } from "./useCommonConfigSnippet";
 export { useCodexCommonConfig } from "./useCodexCommonConfig";
 export { useSpeedTestEndpoints } from "./useSpeedTestEndpoints";
+export { useCodexTomlValidation } from "./useCodexTomlValidation";

src/components/providers/forms/hooks/useCodexTomlValidation.ts

@@ -0,0 +1,75 @@
+import { useState, useCallback, useEffect, useRef } from 'react';
+import TOML from 'smol-toml';
+
+/**
+ * Codex config.toml 格式校验 Hook
+ * 使用 smol-toml 进行实时 TOML 语法校验（带 debounce）
+ */
+export function useCodexTomlValidation() {
+  const [configError, setConfigError] = useState('');
+  const debounceTimerRef = useRef<NodeJS.Timeout | null>(null);
+
+  /**
+   * 校验 TOML 格式
+   * @param tomlText - 待校验的 TOML 文本
+   * @returns 是否校验通过
+   */
+  const validateToml = useCallback((tomlText: string): boolean => {
+    // 空字符串视为合法（允许为空）
+    if (!tomlText.trim()) {
+      setConfigError('');
+      return true;
+    }
+
+    try {
+      TOML.parse(tomlText);
+      setConfigError('');
+      return true;
+    } catch (error) {
+      const errorMessage = error instanceof Error
+        ? error.message
+        : 'TOML 格式错误';
+      setConfigError(errorMessage);
+      return false;
+    }
+  }, []);
+
+  /**
+   * 带 debounce 的校验函数（500ms 延迟）
+   * @param tomlText - 待校验的 TOML 文本
+   */
+  const debouncedValidate = useCallback((tomlText: string) => {
+    // 清除之前的定时器
+    if (debounceTimerRef.current) {
+      clearTimeout(debounceTimerRef.current);
+    }
+
+    // 设置新的定时器
+    debounceTimerRef.current = setTimeout(() => {
+      validateToml(tomlText);
+    }, 500);
+  }, [validateToml]);
+
+  /**
+   * 清空错误信息
+   */
+  const clearError = useCallback(() => {
+    setConfigError('');
+  }, []);
+
+  // 清理定时器
+  useEffect(() => {
+    return () => {
+      if (debounceTimerRef.current) {
+        clearTimeout(debounceTimerRef.current);
+      }
+    };
+  }, []);
+
+  return {
+    configError,
+    validateToml,
+    debouncedValidate,
+    clearError,
+  };
+}