new forge module probes the hive-forge nixos-container (no-op when
absent), and ensures every agent + the manager has a forgejo user
named after them with an access token at `<state>/forge-token`
(visible inside the container as `/state/forge-token`).
idempotent: skips user creation when forgejo reports 'already
exists', skips token issuance when the file is present, scopes the
token to read:user,write:repository,write:issue. token-name suffixed
with a clock so re-issuing doesn't collide with a stale name. shells
out via `nixos-container run hive-forge -- runuser -u forgejo --
forgejo admin` (runuser instead of sudo since sudo isn't in the
container by default).
hooks: ensure_all sweeps existing containers at hive-c0re startup
(backgrounded), and the actions.rs spawn task calls ensure_user_for
the new agent right after lifecycle::spawn succeeds. failures log a
warning but don't abort spawn — a missing token is recoverable from
the next startup sweep.