fix(toml): normalize CJK quotes to prevent parsing errors

Add quote normalization to handle Chinese/fullwidth quotes automatically
converted by IME. This fixes TOML parsing failures when users input
configuration with non-ASCII quotes (" " ' ' etc.).

Changes:
- Add textNormalization utility for quote normalization
- Apply normalization in TOML input handlers (MCP form, Codex config)
- Disable browser auto-correction in Textarea component
- Add defensive normalization in TOML parsing layer

src/utils/textNormalization.ts

@@ -0,0 +1,20 @@
+/**
+ * 将常见的中文/全角/弯引号统一为 ASCII 引号，以避免 TOML 解析失败。
+ * - 双引号：” “ „ ‟ ＂ → "
+ * - 单引号：’ ‘ ＇ → '
+ * 保守起见，不替换书名号/角引号（《》、「」等），避免误伤内容语义。
+ */
+export const normalizeQuotes = (text: string): string => {
+  if (!text) return text;
+  return text
+    // 双引号族 → "
+    .replace(/[“”„‟＂]/g, '"')
+    // 单引号族 → '
+    .replace(/[‘’＇]/g, "'");
+};
+
+/**
+ * 专用于 TOML 文本的归一化；目前等同于 normalizeQuotes，后续可扩展（如空白、行尾等）。
+ */
+export const normalizeTomlText = (text: string): string => normalizeQuotes(text);
+