Add support for custom process patterns

[TheStack-ai]

Context

zclean has built-in patterns for Claude Code and Codex zombie processes. Users may have other AI tools that also leave zombies.

What to do

Support a --pattern flag or .zcleanrc config file that lets users add custom process name patterns to scan for.

Files to modify

• src/scanner.js or src/detector/ (accept custom patterns)
• src/config.js (load config file)

Difficulty: Medium