refactor(client/interface): nui focus tweaks

Add helper functions to set nui focus and restore previous input state.
Ensure focus is reset before triggering responses (promises/callbacks).

resource/interface/client/main.lua

@@ -0,0 +1,12 @@
+local keepInput = IsNuiFocusKeepingInput()
+
+function lib.setNuiFocus(allowInput, disableCursor)
+    keepInput = IsNuiFocusKeepingInput()
+    SetNuiFocus(true, not disableCursor)
+    SetNuiFocusKeepInput(allowInput)
+end
+
+function lib.resetNuiFocus()
+    SetNuiFocus(false, false)
+    SetNuiFocusKeepInput(keepInput)
+end