Pairs with Dialectic.Backend@5cf4302 which removes the backend-driven
broadcaster that was the only consumer of the x-fabric-system-key
header path. Backend cleanup is complete on the consumer side; this
removes the producer-side surface.
Removed:
- ApiKeyGuard: x-fabric-system-key bypass branch (sysExpected /
sysProvided / req.isSystem flag) — only Bearer flow remains.
- messaging.controller.create(): the entire 'if (req.isSystem)'
branch including the SYSTEM_USER_ID='00000000-...-0000' sentinel
persistence path.
- messaging.controller.create(): the 'if (xType === announce) throw
announce_system_only' gate. Announce channels are now ordinary
channels — any participant can POST. Use case: agents post one-off
recruitment broadcasts via fabric-send-message (e.g. dialectic
'come participate in topic X' messages).
- cli/gen-system-api-key.ts: deleted (was the generator for the env
that's no longer read).
Kept:
- channel.purpose field + PATCH /api/channels/:id (member auth for
setting purpose — agents use this to label channels for
fabric-channel-list discoverability).
- cli/print-commands-sync-key.ts (separate key, separate lifecycle).
- GuildRole.isSystem flag (unrelated — system-role permission gate).
hzhang
ca20df7618