fix: rename confg -> config in remove_privacy_info and fix f-string

[ClozyA]

Motivation

• Correct an obvious spelling mistake in the backend config sanitizer to improve readability and prevent future bugs.
• Ensure the privacy-cleanup code is syntactically correct and robust when constructing %APPDATA% paths on Windows.

Description

• Renamed the remove_privacy_info parameter and all internal references from confg to config in app/core/config.py.
• Updated the code that rewrites relative script/config/log paths to use the corrected config variable consistently.
• Fixed the nested-quote usage in the %APPDATA% f-string by switching inner quotes to single quotes so the expression is syntactically valid.
• Preserved original behavior of mapping paths to C:/脚本根目录 and formatting %APPDATA% placeholders.

Testing

• Ran python -m py_compile app/core/config.py, which initially exposed a syntax error from the f-string and then passed after the fix.
• The final python -m py_compile app/core/config.py check completed successfully.

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Codex Task