'talk'    a plain-English turn (`text`). Both sides land on the public
          journal.
'tick'    one bounded cadence beat — it reads the world through its ward,
          decides, acts on the free surfaces, and journals all of it.
'dismiss' retire it and receive the whole export bundle (journal + turns;
          wallet:null — no custody exists at faucet cap 0). Its public page
          and journal keep serving forever.

`signature` is an EIP-191 signature the CALLER produced LOCALLY over the
current familiar(what='auth_message') text — a pass-through string; this
server never sees or holds a key. Call unsigned and the refusal hands back
the exact `sign_this` text + index to sign and retry.