glob tool fails on paths with tilde (~) expansion

The glob tool does not expand ~ (tilde) in the path parameter. Node.js's path.isAbsolute() returns false for paths starting with ~, causing them to be resolved relative to the instance directory instead of the user's home directory.

Steps to reproduce:

1. Run glob with path: ~/.config/opencode
2. Observe: ripgrep execution failed

Expected behavior:
~ and ~/ should be expanded to the user's home directory before resolution.

Root cause:
In packages/opencode/src/tool/glob.ts, line 39:

search = path.isAbsolute(search) ? search : path.resolve(ins.directory, search)

path.isAbsolute(~/.config) returns false, causing the path to be resolved relative to ins.directory.

Tilde expansion already exists elsewhere in the codebase (shell.ts, permission/index.ts) but is missing in the glob tool.