refactor(input): share gamepad map between launcher and gameplay

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

src/core/GamepadMap.lua

@@ -0,0 +1,61 @@
+-- Shared gamepad + raw joystick button tables for launcher and gameplay.
+-- Hardware-measured NX overrides live in NX_* tables (see docs/switch-development.md).
+
+local GamepadMap = {}
+
+-- LÖVE SDL game-controller mapping (D-pad / face / menu).
+GamepadMap.DEFAULT_GAMEPAD_BINDINGS = {
+  dpup = "up", dpdown = "down", dpleft = "left", dpright = "right",
+  a = "a", b = "b",
+  start = "start", back = "select",
+}
+
+-- Generic SDL joysticks without a game-controller DB entry (Linux handhelds).
+GamepadMap.RAW_BUTTON_BINDINGS = {
+  [1] = "a", [2] = "b",
+  [7] = "select", [8] = "start", [9] = "select", [10] = "start",
+}
+
+-- Raw index -> gamepad button name for RomImporter routing.
+GamepadMap.RAW_TO_GAMEPAD_BUTTON = {
+  [1] = "a", [2] = "b",
+  [7] = "back", [8] = "start", [9] = "back", [10] = "start",
+}
+
+-- Test hook: force NX raw tables without stubbing love.
+GamepadMap._forceNXForTests = false
+GamepadMap.NX_RAW_BUTTON_BINDINGS = nil
+GamepadMap.NX_RAW_TO_GAMEPAD_BUTTON = nil
+
+function GamepadMap._setForceNXForTests(v)
+  GamepadMap._forceNXForTests = not not v
+end
+
+local function nxActive()
+  if GamepadMap._forceNXForTests then return true end
+  if love and love._os == "NX" then return true end
+  if love and love.system and love.system.getOS() == "NX" then return true end
+  return false
+end
+
+function GamepadMap.mapGamepadButton(button)
+  return GamepadMap.DEFAULT_GAMEPAD_BINDINGS[button]
+end
+
+function GamepadMap.mapRawButton(index)
+  if nxActive() and GamepadMap.NX_RAW_BUTTON_BINDINGS then
+    local nx = GamepadMap.NX_RAW_BUTTON_BINDINGS[index]
+    if nx then return nx end
+  end
+  return GamepadMap.RAW_BUTTON_BINDINGS[index]
+end
+
+function GamepadMap.mapRawToGamepadButton(index)
+  if nxActive() and GamepadMap.NX_RAW_TO_GAMEPAD_BUTTON then
+    local nx = GamepadMap.NX_RAW_TO_GAMEPAD_BUTTON[index]
+    if nx then return nx end
+  end
+  return GamepadMap.RAW_TO_GAMEPAD_BUTTON[index]
+end
+
+return GamepadMap