fix(q5_max): ensure fallback combo overrides layer locks

Change the fallback combo's action from TO(BASE) to LCK_BASE.
Since LCK_BASE explicitly clears the locked_layers bitmask,
it ensures that the keyboard actually returns to the BASE
layer even if a layer was previously locked.

The previous TO(BASE) action only updated the temporary layer
state, which was immediately overwritten by the persistent
locked_layers bitmask in layer_state_set_user().

keyboards/keychron/q5_max/ansi_encoder/keymaps/via/keymap.c

@@ -228,12 +228,12 @@ const uint16_t PROGMEM encoder_map[][NUM_ENCODERS][2] = {
 // clang-format on
 
 // Combos -----------------------------------------------------------------
-// COMM + DOT + SLSH → TO(BASE): emergency fallback to base layer.
+// COMM + DOT + SLSH → LCK_BASE: emergency fallback to base layer.
 // COMBO_ONLY_FROM_LAYER 0 (config.h) ensures these keycodes are always
 // resolved from BASE so the combo fires regardless of the active layer.
 const uint16_t PROGMEM fallback_combo[] = {KC_COMM, KC_DOT, KC_SLSH, COMBO_END};
 combo_t                key_combos[]     = {
-    COMBO(fallback_combo, TO(BASE)),
+    COMBO(fallback_combo, LCK_BASE),
 };
 
 // Re-assert locked layers whenever QMK modifies layer state (e.g. TT release).