Adds MATTERMOST_REQUIRE_MENTION and MATTERMOST_FREE_RESPONSE_CHANNELS
env vars, matching Discord's existing mention gating pattern.
- MATTERMOST_REQUIRE_MENTION=false: respond to all channel messages
- MATTERMOST_FREE_RESPONSE_CHANNELS=id1,id2: specific channels where
bot responds without @mention even when require_mention is true
- DMs always respond regardless of mention settings
- @mention is now stripped from message text (clean agent input)
7 new tests for mention gating, free-response channels, DM bypass,
and mention stripping. Updated existing test for mention stripping.
Docs: updated mattermost.md with Mention Behavior section,
environment-variables.md with new vars, config.py with metadata.
- test_plugins.py: remove tests for unimplemented plugin command API
(get_plugin_command_handler, register_command never existed)
- test_redact.py: add autouse fixture to clear HERMES_REDACT_SECRETS
env var leaked by cli.py import in other tests
- test_signal.py: same HERMES_REDACT_SECRETS fix for phone redaction
- test_mattermost.py: add @bot_user_id to test messages after the
mention-only filter was added in #2443
- test_context_token_tracking.py: mock resolve_provider_client for
openai-codex provider that requires real OAuth credentials
Full suite: 5893 passed, 0 failed.
Bare strings like "image", "audio", "document" were appended to
media_types, but downstream run.py checks mtype.startswith("image/")
and mtype.startswith("audio/"), which never matched. This caused all
Mattermost file attachments to be silently dropped from vision/STT
processing. Use the actual MIME type from file_info instead.
