Add `hivectl gateway {create-user,delete-user,list-users}` subcommands for
managing htpasswd files used by gateway Basic auth. Pure Rust bcrypt
(cost 12, $2y$ prefix nginx accepts). No external htpasswd binary required.
Also fix the NixOS module assertion: `cfg.auth ? htpasswdFile` is always
true in the module system (declared options always exist as keys); switch
to `nullOr path; default = null` + `!= null` check so the assertion
actually fires with a useful error when enable=true but no file is set.
Guard bind-mount and nginx config against null to prevent eval errors.
Update docs/gateway.md to show hivectl commands instead of raw htpasswd.
systemic gap argus flagged on PR #798 (timeline verb). every `pub fn
run` in hive-forge/src/verbs/*.rs lacked a `# Errors` block —
violates Rust API guidelines + obscures the failure surface for
operators reading the source.
uniform doc per verb category:
- pure GET + print verbs: "transport error from the Forgejo REST call
+ I/O error from stdout"
- body-from-file verbs (comment/comment_edit/issue_create/issue_edit/
pr_create): adds 'I/O error from --body-file/stdin input'
- file-upload verbs (attach-issue, attach-comment): adds 'file
read/exist check'
- pr_create: also mentions the --push shellout
23 `pub fn run` signatures touched. no behaviour change; pure
documentation sweep. cargo test green (38 tests).
