Mentions: restrict “@” parsing to line-start or whitespace to avoid loading from pasted logs

[hannesrudolph]

Type

Enhancement

Summary

Pasting logs that contain “@https://…” or “@/path” mid-line causes the chat to treat them as @-mentions and auto-load URL/file content. Restrict @-mention parsing to line-start or a whitespace boundary to avoid accidental loads from stack traces.

Context

• Affects users when pasting error logs/stack traces into chat.
• Occurs when “@” appears within a line before a URL or absolute path included in logs.
• Desired behavior: Only treat “@” as a mention when at the start of a line, or immediately preceded by whitespace. Keep “@” as an escape to disable mention parsing.

Constraints/Preferences

• Apply the same boundary rule to special mentions like “@problems” and “@Terminal”.
• Consider a setting to disable URL mentions while keeping file/special mentions.

[roomote]

I'm exploring a potential fix for this issue to restrict @-mention parsing to line-start or whitespace boundaries. This will prevent accidental loading of URLs/files from pasted logs. I'll open a PR to share progress.

[roomote]

I've opened PR #7876 with a fix for this issue: #7876

The solution restricts @-mention parsing to only work at line-start or after whitespace, which prevents accidental loading from pasted logs while maintaining full backward compatibility for valid mentions.

All tests are passing locally and CI checks are currently running. Feedback welcome!