Squashes feat/personal-config-dsh-home: personal config.yaml and .env move
from ~/.config/dsh to the Harness home (~/.dsh), plus the module-graph,
lockfile, and i18n pairing regeneration that followed.
Make todo_write opt-in for the tui-agent example (disabled by default; TUI
still renders plans when the tool is loaded). Both enabled and disabled cases
covered by tests.
Turtle