[Bug] Edit tool strips trailing whitespace, breaking Markdown line breaks

Bug Description
Title: Edit tool strips trailing whitespace, breaking Markdown line breaks

Description:

The Edit tool automatically strips trailing whitespace from lines before writing to files. This breaks Markdown formatting where two trailing spaces are required for soft line breaks.

Example use case:
User stories with WHEN/THEN acceptance criteria format:

• WHEN condition,

THEN result.

The two spaces after the comma are required for proper rendering in Markdown preview, but the Edit tool removes them.

Expected behavior:
Preserve trailing whitespace as provided in the new_string parameter.

Workaround:
Users must manually add trailing spaces in their IDE after Claude Code edits the file.

Environment Info

• Platform: darwin
• Terminal: phpstorm
• Version: 2.1.1
• Feedback ID: 95d9f7b1-fb42-44a2-b249-436f5a82171f

Errors

[{"error":"Error\n    at eP (/$bunfs/root/claude:59:1144)\n    at <anonymous> (/$bunfs/root/claude:60:10098)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:861:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:27.402Z"},{"error":"Error\n    at eP (/$bunfs/root/claude:59:1144)\n    at <anonymous> (/$bunfs/root/claude:60:10098)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:861:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:27.403Z"},{"error":"Error\n    at eP (/$bunfs/root/claude:59:1144)\n    at <anonymous> (/$bunfs/root/claude:60:10098)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:861:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:27.442Z"},{"error":"Error\n    at eP (/$bunfs/root/claude:59:1144)\n    at <anonymous> (/$bunfs/root/claude:60:10098)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:861:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:27.842Z"},{"error":"Error\n    at eP (/$bunfs/root/claude:59:1144)\n    at <anonymous> (/$bunfs/root/claude:60:10098)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:861:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:48.351Z"},{"error":"Error\n    at eP (/$bunfs/root/claude:59:1144)\n    at <anonymous> (/$bunfs/root/claude:60:10098)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:861:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:48.581Z"},{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/jansamek/.local/share/claude/versions/2.1.2 (expected in multi-process scenarios)\n    at oXR (/$bunfs/root/claude:2994:2164)\n    at PQB (/$bunfs/root/claude:2992:35188)\n    at async er7 (/$bunfs/root/claude:2992:38896)\n    at async mj (/$bunfs/root/claude:2994:236)\n    at async <anonymous> (/$bunfs/root/claude:2994:14358)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:37:56.906Z"},{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/jansamek/.local/share/claude/versions/2.1.2 (expected in multi-process scenarios)\n    at oXR (/$bunfs/root/claude:2994:2164)\n    at PQB (/$bunfs/root/claude:2992:35188)\n    at async er7 (/$bunfs/root/claude:2992:38896)\n    at async mj (/$bunfs/root/claude:2994:236)\n    at async <anonymous> (/$bunfs/root/claude:2994:14358)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:38:56.124Z"},{"error":"Error: Request was aborted.\n    at _createMessage (/$bunfs/root/claude:446:3157)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-09T09:40:34.397Z"},{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/jansamek/.local/share/claude/versions/2.1.2 (expected in multi-process scenarios)\n    at oXR (/$bunfs/root/claude:2994:2164)\n    at PQB (/$bunfs/root/claude:2992:35188)\n    at async er7 (/$bunfs/root/claude:2992:38896)\n    at async mj (/$bunfs/root/claude:2994:236)\n    at async <anonymous> (/$bunfs/root/claude:2994:14358)\n    at processTicksAndRejections (native:7:39)

Note: Error logs were truncated.