Glob tool silently fails when pattern contains ~

Summary

The Glob tool returns empty results (no error) when the pattern contains ~, because ~ is not expanded in the pattern parameter. This is a UX bug - the silent failure makes debugging difficult.

Reproduction

# Fails silently - returns "No files found"
Glob(pattern="~/.claude/commands/**/tdd*")

# Works - ~ expanded in path parameter
Glob(pattern="**/tdd*", path="~/.claude/commands")

Expected Behavior

Either:

1. Expand ~ in the pattern parameter (match shell behavior)
2. Return an error/warning when ~ detected in pattern: "pattern contains ~, did you mean to use the path parameter?"

Actual Behavior

Returns "No files found" with no indication that ~ wasn't expanded.

Impact

• Silent failure mode is confusing
• Even Claude Opus didn't catch this initially, suggesting other models/users will struggle
• Users may incorrectly conclude the file doesn't exist

Environment

• Claude Code CLI
• Glob tool