forked from 1b-agent/opencadstudio-upstream
Bare `UCS` now enters an interactive front-end (UcsCommand) that gathers the option then its value as separate steps, instead of the command line submitting `UCS` alone on the first Space. The front-end delegates execution back to the existing inline `UCS <option> …` handler via a new `CmdResult::Dispatch(String)`, so the coordinate-system math and the save/persist path are untouched. Now `UCS Z 90` works the same from the command line (Space-separated), headless automation, and any source that feeds the active command — closing the input half of #169. Inline `UCS Z 90` (one-shot / paste) still hits the inline handler directly. Second phase of routing input sources through the unified step driver: the interactive command is driven by feed_command like any tool. Adds headless test ucs_interactive_inline_args. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>