[argiad]

Follow-up to #157. The live test of #157 found one unused session on the owner account (@admin) and a second session on @mm-core. This PR stops the installer creating them.

Cause

Synapse's shared-secret registration (/_synapse/admin/v1/register) also signs the new account in, creating a device and an access token, unless the request sets inhibit_login. register_new_matrix_user has no option for that, and it throws the token away. So every install so far has left:

• one session on the owner account that nobody ever used. It shows up in the owner's Matrix app under its list of sessions.
• one on @mm-core, since fix(deploy): close five self-host installer gaps; mmctl upgrade --to; mm-core's own Synapse account #157.

Fix

_register_user (deploy/lib/bootstrap.sh) now does the same handshake itself, with inhibit_login: true:

1. get a nonce;
2. compute HMAC-SHA1 over nonce, user, password and admin, keyed with registration_shared_secret;
3. POST the registration.

It runs as a short standard-library Python script under Synapse's own Python, inside its container, the way register_new_matrix_user runs. Behaviour is otherwise the same:

• the password reaches it on stdin only;
• an account that already exists fails with Synapse's answer (M_USER_IN_USE);
• an unreachable Synapse fails with a one-line message, not a traceback.

Existing installs

Installs from before keep that one session on the owner account. It has no name, and "last seen" is empty, so signing it out from the app is safe; the CHANGELOG says so. The installer leaves the owner's sessions alone: telling this session apart from a real one relies on a heuristic, and #157 settled that a re-run leaves the owner account alone.

Tests

• 5 new bats tests, each seen failing first. They run against deploy/test/fixtures/fake_synapse_register.py, a fake Synapse that checks the MAC as v1.163 does and records whether a device was created. Removing inhibit_login fails 2 of them.
• Full suite 352/352, shellcheck clean (macOS bash 3.2).
• Checked against a real matrixdotorg/synapse:v1.163.0 container (local, now removed). Its generated config has a quoted secret with symbols, which the parser handled. Results:
  • an owner account registered this way had 0 devices;
  • @mm-core had only the 1 sign-in I made;
  • an account registered with register_new_matrix_user, for comparison, had an extra never-used device (last_seen_ts: null);
  • the exact password, with quotes, a backslash and non-ASCII, signs in;
  • the account is an admin.

🤖 Generated with Claude Code