cleanup: final purge of legacy files and default config tuning

Author: fqjony

concept copy.md

@@ -2,7 +2,6 @@ quiet = false
 exec.prompt = ai.codex.min
 exec.stream = false
 ai.enabled = false
-capture.mode = global
 install.path_prompt = true
 developer.enabled = false
 state_path = ~/.udx/dev.kit/state