Ticket 106 asked for a real way for API handlers to address the
primary vs. profile actor. That routing was already built out of
necessity while landing tickets 104/105 (metric queries had to reach
the profile actor's snapshot for those tickets' own tests to pass) --
EngineHandle ended up as one combined handle (option (b) from the
ticket's own scope note) that internally proxies metric/alert writes
to the profile actor and routes MetricDeclarations/BucketValues/Promql
reads to its snapshot, with no changes needed to any API handler,
reload_engine_declarations/activate_profile, or Profile::load_into_engine
-- they already just send EngineMessages the same way they did before
the split. mcp_server.rs talks to the HTTP API rather than EngineHandle
directly, so it needed no changes either. This commit documents that
resolution in handle.rs so a future reader doesn't go looking for
routing logic that isn't there.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TeyhRfMYjMditek6geDRoQ
