Fix route-based port mapping: use hostPort as container port

allocateRoutePorts() was using the route's port field (the mc-proxy
listener port, e.g. 443) as the container internal port in the podman
port mapping. For L7 routes, apps don't listen on the mc-proxy port —
they read $PORT (set to the assigned host port) and listen on that.

The mapping host:53204 → container:443 fails because nothing listens
on 443 inside the container. Fix: use hostPort as both the host and
container port, so $PORT = host port = container port.

Broke mcdoc in production (manually fixed, now permanently fixed).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

proto/mcp/v1/mcp.proto

@@ -38,7 +38,7 @@ service McpAgentService {
 
 message RouteSpec {
   string name = 1;      // route name (used for $PORT_<NAME>)
-  int32 port = 2;       // external port on mc-proxy
+  int32 port = 2;       // mc-proxy listener port (e.g. 443, 8443, 9443); NOT the container internal port
   string mode = 3;      // "l4" or "l7"
   string hostname = 4;  // optional public hostname override
 }