Found Founding

The founder's approval: start founding from reviewing (spec §4.3, D5).

Same SSE response shape as /turn — the founder watches checklist frames on this stream, done last, always. Same claim discipline too: the claim is taken before the status code is chosen, so a concurrent segment gets a real 409 the client re-attaches on.

Caps were counted at naming; the finalizer's stall-don't-fail gate check (step 3) is unchanged and still protects credits/plan/pause at the handoff. Standing to found (spec CREDIT_NOTICES D13): (a Founder plan OR a live trial) AND at least 12 credits — checked here, before the claim, as a typed 402 whose payload is the flip card the review screen renders in FOUND's place.

The v3 welcome grant (spec V3_GA_FLIP D2) fires FIRST, unconditionally, once per conglomerate ever: a first-time presser banks 15 credits before the gate reads the balance, so a fresh trial account founds without a top-up. The conglomerate is re-loaded after it so the gate sees the fresh balance.