* fix(mcp): resolve call_tool by registry without requiring tool map
Multi-worker reloads put MCP servers in the registry from the DB but do
not re-run tools/list on every process. Gating call_tool on
tool_name_to_mcp_server_name_mapping made cold workers 500 with Tool not
found after another worker had already listed the tool. Treat a registry
match on server id/name/alias as enough; upstream rejects unknown tools
* test(e2e): poll MCP register, tools/list, and tools/call across multi-worker lag
Stage multi-worker gateways only load MCP servers and tool maps on the
process that handled the request. Poll until the server is listed, the
tool appears on tools/list, and tools/call is not a cold-worker 500 so
key-access and Datadog MCP e2e stop racing the LB
* Revert "fix(mcp): resolve call_tool by registry without requiring tool map"
This reverts commit 8b56e51e39.
* test(e2e): tighten MCP multi-worker lag classifier
Only retry tools/call on gateway shapes Tool <name> not found and
server_not_found, not any 500 that mentions tool/server not found, so
upstream failures are not retried until the poll deadline
* test(e2e): drop unit file for MCP lag classifier
The live await_call_tool polls already cover multi-worker lag; a separate
string-match unit module is not worth keeping
c274cf321c