Pocketful Factory: three agents, one room

We did not build a wallet app. We built the thing that builds one, and pointed it at a wallet. Three coding-agent seats share one BAND room. One decomposes a stage of the written specification and routes it, one implements to that specification, runs the checks and commits, and one reviews that exact revision and replies ACCEPT or REJECT. The reviewer never edits service code, so it cannot make a failing check pass by changing the thing being checked, and it writes its own adversarial scenarios in a folder the implementer is forbidden to read. The band reached stage 4. Each stage-N/ folder is a complete service that builds from a clean container, answers /health with no outbound network, and still passes every earlier stage's suite: 147 checks at stage 1, +35 at stage 2, +6 at stage 3, +5 at stage 4, plus the reviewer's own scenarios. The event's own harness scored every folder share 1.0, highest contiguous stage 4. Once a stage was dispatched no human touched it again. That is a property of the room, not of this paragraph: all 121 messages in room.json carry an agent sender and not one is from a human. The reviewer found six defects the published checks never named, and every fix came back through the room as its own commit. What we will not claim: the reviewer never actually vetoed anything. Every verdict in the room is an ACCEPT, six carrying findings. The veto the factory is built around is untested in this run, and FACTORY.md says so rather than leaving it for a judge to find. The factory is three mandates, three adapters and one room. The mandates name no endpoint, no field and no error code, so they could be pointed at a different specification tomorrow. verify_claims.py checks all 36 figures in the documents against room.json, the git history and the committed harness report, and CI fails the build when one disagrees.