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

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

tests/engine/input_shared_map_test.lua

@@ -0,0 +1,45 @@
+-- Shared gamepad/raw map: launcher and gameplay use identical converters (SWNX-10/11).
+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 check = T.check
+local eq = T.eq
+
+local GamepadMap = require("src.core.GamepadMap")
+local Input = require("src.core.Input")
+local RomImporter = require("src.import.RomImporter")
+
+-- Gamepad names map to GB actions.
+eq(GamepadMap.mapGamepadButton("a"), "a", "gamepad A -> GB A")
+eq(GamepadMap.mapGamepadButton("back"), "select", "gamepad back -> select")
+eq(GamepadMap.mapGamepadButton("dpup"), "up", "gamepad d-pad up")
+
+-- Generic raw indices (Linux handheld fallback).
+eq(GamepadMap.mapRawButton(1), "a", "raw #1 -> A")
+eq(GamepadMap.mapRawButton(8), "start", "raw #8 -> start")
+eq(GamepadMap.mapRawToGamepadButton(2), "b", "raw #2 routes to gamepad b")
+
+-- Input and RomImporter agree on the same GB action for a raw press.
+Input:init()
+Input:joystickpressed(nil, 1)
+Input:step()
+check(Input:isDown("a"), "Input raw #1 holds A")
+
+local importer = setmetatable({
+  _padCursor = { x = 0, y = 0 }, _padCursorActive = false,
+  _padAxis = { leftx = 0, lefty = 0, righty = 0 },
+  _padDir = {}, _rawHatDirs = {}, _padInited = true,
+}, RomImporter)
+local clicked = false
+function importer:mousepressed(_, _, button)
+  clicked = button == 1
+end
+importer:joystickpressed(nil, 1)
+check(clicked, "RomImporter raw #1 clicks via shared map (not hardcoded-only)")
+
+importer:joystickpressed(nil, 2)
+check(importer._padDir.dpright == nil,
+  "raw #2 maps to B, not spurious d-pad")
+
+T.finish()