chengyongru f44ee6cb27 fix(signal): bypass base is_allowed for policy-approved messages
Override _handle_message to publish directly to the bus for messages
that have already passed _check_inbound_policy. The denied DM pairing
path calls super()._handle_message() to issue pairing codes via the
base class. This avoids cross-policy leakage where e.g. group open
policy would cause is_allowed to incorrectly allow denied DM senders.

Also includes:
- SSE: strip one optional leading space after 'data:' per spec
- Convert 20+ f-string log calls to loguru lazy formatting
- Add end-to-end tests for DM/group routing through the full chain
- Add cross-policy test (dm allowlist + group open) for pairing
- Add Signal channel documentation to docs/chat-apps.md
2026-05-20 22:57:49 +08:00
..