aivm: state the handler contract as it is, not as one case of it

The rule is that a handler must not dispatch on the request path, because the
node delivers the path the request arrived on. A flat map of endpoints answering
at their mounts is the simplest shape that satisfies it, and this VM uses it —
but an endpoint also owns the paths beneath it, and a VM that wants a subtree may
mount once and read the remainder. Both are served. Writing the simple case as if
it were the only one made the comment false the moment the other landed.

Co-authored-by: Hanzo Dev <[email protected]>

aivm/vm.go

@@ -403,7 +403,18 @@ func (vm *VM) Shutdown(ctx context.Context) error {
 	return nil
 }
 
-// CreateHandlers returns HTTP handlers
+// CreateHandlers returns one entry per endpoint.
+//
+// The node mounts each KEY as a route and delivers the request on the path it
+// arrived on, so a handler that dispatches on r.URL.Path never matches: it is
+// asked for /v1/bc/<chainID>/rpc and looks for /stats. A flat map of endpoints to
+// handlers that answer AT their mount is the simplest shape that works, and it is
+// what this VM uses.
+//
+// It is not the only shape. An endpoint also owns the paths beneath it, and a VM
+// that wants a subtree may mount one handler and read the remainder — the node
+// strips the mount before handing it over (node server/http/router.go,
+// serveBelowMount). Both are served; a VM picks whichever matches its surface.
 func (vm *VM) CreateHandlers(context.Context) (map[string]http.Handler, error) {
 	return Routes(vm), nil
 }