feat: add laptop/display brightness modulation

kernel/src/Api/Syscall.cpp

@@ -207,7 +207,7 @@ namespace montauk::abi {
                 return Sys_DisplaySetMode((int)frame->arg1);
             case SYS_DISPLAYBRIGHTNESS:
                 if ((int64_t)frame->arg1 >= 0 &&
-                    !Sched::Consent::Require(CAP_DISPLAY_ADMIN)) return CapabilityDenied;
+                    !Sched::Consent::Require(CAP_BRIGHTNESS)) return CapabilityDenied;
                 return Sys_DisplayBrightness((int)frame->arg1);
             case SYS_GETEXECPATH:
                 if (!UserMemory::Range(frame->arg2 ? frame->arg1 : frame->arg1, frame->arg2, true)) return BadPointer;