Touch: list the keyboard button in the default layout so the editor offers it

Adding the TouchButtonId was not enough. The editor offers what the LAYOUT contains, not what
the enum declares, so the button existed and did nothing visible -- reported straight away.

Listed with enabled = false alongside the save/load/screenshot buttons, which is the same
opt-in shape. Existing layouts pick it up without being disturbed: TouchLayout.fromJson
splices in any default button a saved layout lacks, and defaultPortrait splices from this
same table, so one entry covers both orientations and everyone's current layouts.

android/armsx3-ui/app/src/main/java/com/armsx2/ui/touch/TouchControls.kt

@@ -1502,6 +1502,12 @@ data class TouchLayout(val buttons: List<TouchButtonCfg>) {
                 TouchButtonCfg(TouchButtonId.SAVE_STATE, 0.30f, 0.54f, 44f, enabled = false),
                 TouchButtonCfg(TouchButtonId.LOAD_STATE, 0.38f, 0.54f, 44f, enabled = false),
                 TouchButtonCfg(TouchButtonId.SCREENSHOT, 0.46f, 0.54f, 44f, enabled = false),
+                // On-screen keyboard toggle -- OPT-IN, same row. Being listed here is what makes it
+                // reachable at all: the editor offers what the layout CONTAINS, not what the enum
+                // declares, so adding the TouchButtonId alone left it invisible. Existing layouts
+                // pick it up because fromJson splices in any default button they lack, and
+                // defaultPortrait splices from this same table.
+                TouchButtonCfg(TouchButtonId.KEYBOARD, 0.54f, 0.54f, 44f, enabled = false),
                 // Extra analog button, parked directly above the D-PAD (0.10, 0.55) — not above the
                 // left stick, which is where it first went. The button is for sprint/jump held while
                 // you keep moving, so it belongs above whichever control the thumb is already on,