* fix(#2201): accept --phase N flag in the phase verb family (complete, list-plans)
The phase family router treated the first positional (args[2]) as the phase
number, so `phase complete --phase 12` passed the literal '--phase' as the phase
→ 'Phase --phase not found'. The state family already accepted --phase N. Now
complete and list-plans accept --phase N (and --phase=N) as well as the bare
positional; unrecognized flags yield a usage error naming the accepted form.
Closes#2201
* docs(#2201): add changeset fragment
* docs(#2201): backfill PR number
