add non-VK Undo/Cut/Copy/Paste keycodes

src/input.cpp

@@ -758,7 +758,13 @@ namespace input {
     }
 
     auto release = util::endian::little(packet->header.magic) == KEY_UP_EVENT_MAGIC;
-    auto keyCode = packet->keyCode & 0x00FF;
+    auto keyCode = util::endian::little(packet->keyCode);
+
+    // Preserve full-width keycodes for Sunshine non-normalized keyboard events.
+    // Normalized keycodes are legacy VK values and only use the low 8 bits.
+    if (!(packet->flags & SS_KBE_FLAG_NON_NORMALIZED)) {
+      keyCode &= 0x00FF;
+    }
 
     // Set synthetic modifier flags if the keyboard packet is requesting modifier
     // keys that are not current pressed.

src/platform/linux/input/inputtino_keyboard.cpp

@@ -157,7 +157,12 @@ namespace platf::keyboard {
     {KEY_BACKSLASH, 0xDC},
     {KEY_RIGHTBRACE, 0xDD},
     {KEY_APOSTROPHE, 0xDE},
-    {KEY_102ND, 0xE2}
+    {KEY_102ND, 0xE2},
+    // Sunshine extension keycodes (sent with SS_KBE_FLAG_NON_NORMALIZED)
+    {KEY_UNDO, 0x100},
+    {KEY_CUT, 0x101},
+    {KEY_COPY, 0x102},
+    {KEY_PASTE, 0x103}
   };
 
   void update(input_raw_t *raw, uint16_t modcode, bool release, uint8_t flags) {