Scenarios install their Galaxy dependencies with `force: true`, so two roles
running at once re-extract the same collections and roles into ~/.ansible and
pull them out from under each other mid-play. It surfaces as a collection that
was working moments earlier going missing:

  the connection plugin 'community.docker.docker' was not found

Found while running five scenarios in parallel, where it cost a run.

ANSIBLE_HOME relocates both `collections/` and `roles/`, so one variable covers
both halves; the scenarios' ANSIBLE_ROLES_PATH workaround now follows it rather
than hardcoding ~/.ansible/roles. Left alone if already set, and unset in CI,
where each role runs in its own job and has nothing to collide with.

Verified by removing var/molecule-ansible-home entirely and running
matrix-alertmanager-receiver from cold: green through idempotence, with the
collections and roles landing under the per-role directory - which also shows
nothing was quietly relying on the shared ~/.ansible being populated.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SEH3vxYSQ5SV4N5z61eyGT

baibot is the first bot rather than a bridge, and the shape
differs from the appservices: it is a plain Matrix client that logs in with a
password, sets up its profile and then syncs. It publishes no port, so nothing
can be probed over HTTP; what it says about itself in the journal is the only
window into whether the role's configuration reached the process.

What the scenario proves:

- The unit is active with no automatic restarts, AND baibot got past startup
  into its sync loop. The second half is what carries the scenario. baibot never
  exits when startup goes wrong - it retries the failing step forever with a
  growing delay - so the unit sits there `active` with `NRestarts` at 0 while
  the bot is permanently half-started. Pointing `user.avatar` at a file that is
  not there reproduces exactly that: the unit assertion still passes, the sync
  assertion does not.
- The display name the bot announces it wants is the role's `user.name`, which
  is neither the role's default nor what the stub reports the account already
  has.
- The rendered `logging` string took effect per target: baibot's own records
  appear at DEBUG (the role ships `info`) while everything underneath stays at
  the `warn` catch-all. The second half is the control, and raising the
  catch-all turns 2 DEBUG records into 161.
- The rendered config carries the scenario's homeserver, identity, command
  prefix, admin patterns and user patterns, and uses password authentication
  exclusively, with the access-token keys rendered as nulls.
- The statically-defined agent survived the provider templating - the
  per-provider template rendered to YAML, parsed, merged and nested into the
  list - key by key.
- The container runs as the uid/gid the playbook supplies (1234, not the 1000
  the base image already has), on the image version defaults/main.yml pins, and
  could write its session into the data path.

No AI provider is contacted and none is needed. baibot calls a provider only
when a message asks an agent to do something, so a static agent with a
placeholder key and a base URL that resolves nowhere still has to survive the
bot's startup parsing - which is the part worth testing.

The shared stub grew what a syncing Matrix client needs and an appservice did
not: /sync (with a `next_batch`, and holding the call open for the timeout the
client asked for, or the bot spins the stub in a hot loop), the media config
and upload endpoints a bot setting its own avatar insists on, /keys/upload with
its key counts, and filter creation. Without the media config in particular,
baibot never gets past profile setup.

The shared stub task gained a STUB_VERBOSE knob. The stub already advertised
the environment variable but there was no way to set it from a scenario, and
for a component with no port of its own its request log is the only place to
see what the component is actually asking for.

Note: molecule-shared/homeserver-stub.py also carries a loosened /login match
from another scenario being written in this same tree at the same time; it was
already in the working copy and is not mine.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SEH3vxYSQ5SV4N5z61eyGT