* fix(mcp): fail durable tasks whose connection no longer resolves
A personal MCP runtime name is derived from the server's complete definition, and a deployment task server belongs to the Gateway startup snapshot. Editing, disabling, or deleting a personal server while a durable task is in flight therefore makes the persisted server name unresolvable. McpTaskToolCaller raised LookupError, which the service classifies as transient: status polls and cancellation retried forever, leaving the task stuck in working and impossible to cancel.
Raise a dedicated McpTaskConnectionUnavailableError instead, and terminalize it: status polls persist failed with the connection error and stop; a pending cancellation persists failed locally because the remote task can no longer be reached. Transient status/cancel errors keep their existing capped-backoff retry policy.
Tests: new service tests pin both terminal paths, and caller tests pin the exception for missing deployment and stale personal server names.
* fix(mcp): preserve LookupError compatibility for connection errors
McpTaskConnectionUnavailableError now subclasses LookupError instead of RuntimeError. The four existing personal-MCP assertions in test_personal_mcp.py still treat a missing or stale connection as a lookup failure; keeping that base preserves their behavior and avoids breaking callers that caught the previous type, while the task service still catches this exact type for permanent-failure classification.
Add a compatibility test and rerun the personal-MCP and task suites.
---------
Co-authored-by: Tong-bit-art <Tong-bit-art@users.noreply.github.com>
eed7fa8f05