Edit tool converts Unicode typographic apostrophes to ASCII apostrophes

Description

When using the Edit tool to write text containing Unicode typographic apostrophes (' U+2019), they are being converted to ASCII apostrophes (' U+0027). This causes syntax errors in languages like PHP where single quotes delimit strings.

Steps to Reproduce

1. Read a PHP file containing strings with typographic apostrophes (e.g., 'Carta d'identità')
2. Use the Edit tool to write new content that includes the same strings
3. The typographic apostrophes (' = E2 80 99 in UTF-8) are converted to ASCII apostrophes (' = 27 in hex)

Expected Behavior

Unicode characters should be preserved exactly as written, maintaining the original encoding.

Actual Behavior

Typographic apostrophes are converted to ASCII apostrophes, breaking PHP string syntax.

Example

Original (working):

label: 'Carta d'identità (Rappresentante Legale)'

Hex: 64e2 8099 69 for d'i

After Edit tool:

label: 'Carta d'identità (Rappresentante Legale)'  

Hex: 6427 69 for d'i

This results in PHP parse error: unexpected identifier "identità", expecting ")" because the ASCII apostrophe closes the string prematurely.

Environment

• Claude Code CLI
• Model: Claude Opus 4.5
• Platform: Linux