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.
Full Docusaurus docs following the Discord guide structure:
Mattermost (277 lines):
- Step-by-step: enable bot accounts, create bot, get token, add to channels
- All env vars documented with examples
- Reply mode (thread/off), home channel, troubleshooting
Matrix (354 lines):
- Step-by-step: create bot account, get access token (Element or API)
- Dual auth (token + password), E2EE section with libolm install
- Thread support, DM detection, home room, troubleshooting
- Works with any homeserver (Synapse, Conduit, Dendrite, matrix.org)
