Chinese IME input inside string literals causes garbled pinyin characters to appear in SQL editor

### Description

When this happens, a pop-up error will appear：
TypeError

### Steps to reproduce

1、Open a SQL editor and connect to a database
2、Type a single quote ' to start a string literal
3、Switch to a Chinese IME (e.g. Pinyin)
4、Start typing Chinese characters inside the quotes

### Expected/Desired Behavior

During composition, only the IME candidate text should appear at the cursor position. After confirming the composition, the final Chinese characters should be inserted into the string literal.

### CloudBeaver Version

CloudBeaver 26.1.3

### Additional context

During composition, raw pinyin intermediate characters (e.g. 'z'c'f'z'b) appear directly in the editor content alongside the IME composition UI. The result is garbled: 'z'c'f'z'b资产负债表'.
Important:
This does not happen when the SQL editor is disconnected from the database (no SQL language support loaded)