Add an e2e suite at tests/e2e/mcp/ that proves MCP authorization over the
api_key auth family. An admin registers an upstream MCP server through the
management API (POST /v1/mcp/server, persisted in the DB and picked up without
a restart) and queues its deletion. Two keys are created against that one
server: one granted access through object_permission.mcp_servers and one with
no MCP grant. The permitted key is a live control proving the upstream is
reachable and the tool is callable, so a denial on the ungranted key is an
authorization decision rather than a dead server. The denied key then sees
none of the server's tools on tools/list and is refused a tools/call with a
403 access_denied.
A deterministic self-hosted FastMCP upstream (add/multiply over
streamable-http) is added to the e2e compose stack so the suite runs offline
with a known tool set. KeyGenerateBody gains an optional typed
object_permission so the shared gateway can create a key with an MCP grant.