feat: add directory creation from picker via customizable hook

[dcadenas]

Summary

Create directories directly from the picker by typing a name and pressing Enter (or Ctrl+Enter if matches exist). Supports git init and cloning from GitHub/GitLab URLs.

Changes

• Show dynamic hint for creation options
• Convention-based hook at ~/.config/tms/create-hook
• Hook can return custom directory name via stdout
• Default hook: creates directory with git init
• Enhanced hook: detects and clones GitHub/GitLab URLs
• Ctrl+Enter to force creation when matches exist
• Auto-creates hook on first use

Hook Features

Git URL detection:

• Type https://github.com/user/repo → clones repo → opens session "repo"
• Type https://gitlab.com/user/project → clones → opens "project"

Customizable output:

• Hook returns directory name via stdout (optional)
• Falls back to typed name if no output
• Enables URL → repo name transformation

Force creation:

• No matches: Enter creates
• Matches exist: Ctrl+Enter creates, Enter selects match
• Compact hints: [^↵: create foo, ↵: open foobar]

Testing

All tests pass. Tested with git init, GitHub/GitLab clones, and force creation.

[dcadenas]

This relates to #114