test(nx-mods): lock zip and chord edge regressions

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

tests/engine/game_display_chord_test.lua

@@ -114,6 +114,25 @@ Game:gamepadpressed(joySelectDown, "y")
 eq(digits[1], "5", "Select via isGamepadDown(back) + Y -> 5")
 eq(#padForwarded, 0, "isGamepadDown Select chord does not forward face")
 
+-- Edge: every chord face without Select must not cycle (NXMOD-09)
+GamepadMap._setForceNXForTests(false)
+for _, btn in ipairs({ "a", "b", "y", "x", "leftshoulder" }) do
+  Input:init()
+  resetSpies()
+  Game:gamepadpressed(joy, btn)
+  eq(#digits, 0, "edge: no cycle without Select for " .. btn)
+  eq(#padForwarded, 1, "edge: " .. btn .. " still reaches Input without Select")
+  check(not wroteOptions, "edge: no options write without Select for " .. btn)
+end
+
+-- Edge: Select alone (no face) does not synthesize a digit
+holdSelect()
+resetSpies()
+-- pressing back again while held is not a display chord partner
+Game:gamepadpressed(joy, "back")
+eq(#digits, 0, "edge: Select alone does not fire a display digit")
+eq(#padForwarded, 1, "edge: Select alone still forwards to Input")
+
 GamepadMap._setForceNXForTests(false)
 Game.keypressed = origKeypressed
 Input.gamepadpressed = origPad

tests/engine/input_display_chord_test.lua

@@ -40,4 +40,10 @@ eq(GamepadMap.displayChordDigit("x"), "6", "NX X -> key 6")
 eq(GamepadMap.displayChordDigit("leftshoulder"), "7", "NX L -> key 7")
 GamepadMap._setForceNXForTests(false)
 
+-- Edge: map alone never invents a digit for non-chord faces (NXMOD-09 map half)
+for _, btn in ipairs({ "guide", "leftstick", "rightstick", "lefttrigger" }) do
+  eq(GamepadMap.displayChordDigit(btn), nil,
+    "edge: unmapped " .. btn .. " is not a display digit")
+end
+
 T.finish()