In multi-user mode, plugin task requests are published to a Redis channel
keyed by user token. When no MCP server instance held a plugin connection
for that token (e.g. after the user navigated away from the workspace),
the publish reached zero subscribers and the request was silently dropped,
so every tool call stalled until the 30-second task timeout instead of
failing with a meaningful error.
RedisBridge.sendTaskRequest now returns the PUBLISH receiver count and
releases its response-channel subscription when the request reached no
receiver (or publishing failed), since no response can arrive. PluginBridge
uses the count to reject the pending task immediately with the multi-user
connection error message; publish failures likewise reject the task instead
of surfacing as an unhandled rejection followed by a timeout. The pending-
task settlement logic shared with the timeout handler is extracted into a
rejectPendingTask helper.
AI-assisted-by: claude-fable-5
Read PENPOT_TENANT env var (defaulting to "default") and embed it in
Redis Pub/Sub channel names as penpot.mcp.<tenant>.task.{req,res}.<id>.
This prevents cross-tenant interference when multiple environments share
a Redis instance, matching the backend convention
(e.g. penpot.rlimit.<tenant>.window.<name> in app.rpc.rlimit).
Co-authored-by: deepseek-v4-flash <deepseek-v4-flash@penpot.app>
