fix(input): apply Switch-measured controller fallback

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/engine/input_nx_raw_map_test.lua

@@ -0,0 +1,22 @@
+-- NX raw fallback indices measured on OLED hardware (SWNX-11).
+package.path = "./?.lua;./?/init.lua;" .. package.path
+if not _G.love then _G.love = require("tests.love_stub") end
+
+local T = require("tests.harness")
+local eq = T.eq
+
+local GamepadMap = require("src.core.GamepadMap")
+
+GamepadMap._setForceNXForTests(true)
+
+-- Phase 0 probe: Y→#3, X→#4; Nintendo B/A at #1/#2.
+eq(GamepadMap.mapRawButton(3), "b", "NX raw Y (#3) maps to GB B")
+eq(GamepadMap.mapRawButton(4), "a", "NX raw X (#4) maps to GB A")
+eq(GamepadMap.mapRawToGamepadButton(3), "y", "NX raw #3 routes to gamepad y")
+eq(GamepadMap.mapRawToGamepadButton(4), "x", "NX raw #4 routes to gamepad x")
+eq(GamepadMap.mapRawButton(9), "select", "NX minus (#9) -> select")
+eq(GamepadMap.mapRawButton(10), "start", "NX plus (#10) -> start")
+
+GamepadMap._setForceNXForTests(false)
+
+T.finish()