feat: implement kernel capability model

kernel/src/Api/Power.hpp

@@ -31,6 +31,11 @@ namespace montauk::abi {
     // action; any other value records it as the pending action. Returns the
     // pending action for queries, or 0 when recording one.
     static int64_t Sys_PowerRequest(int action) {
+        // Polled by the session leader every second; deliberately silent and
+        // non-destructive, so it neither floods the log nor races login for
+        // the request it is about to hand over by exiting.
+        if (action == POWER_REQ_PEEK) return (int64_t)g_pendingPowerAction;
+
         if (action == POWER_REQ_QUERY) {
             int pending = g_pendingPowerAction;
             g_pendingPowerAction = POWER_REQ_QUERY;