fix(selection): sync prev_click_down before early returns

Previously, set_enabled(false) caused prev_click_down to drift, so a
click that spanned a disable/enable window would be silently dropped.
Move release-edge sync above early returns; handle click_action==nil
guard inline so is_action_down isn't called with nil.

init.lua

@@ -308,14 +308,15 @@ end
 -- Per-Frame
 
 function M.update(dt)
-    if not enabled_flag then return end
-    if click_action == nil then return end
-
-    -- Release-edge detection (lib-core.input has no was_action_released).
-    local cur_down = input.is_action_down(click_action)
+    -- Release-edge detection must sync EVERY frame (even when disabled or unbound)
+    -- so prev_click_down doesn't drift across enable/disable boundaries.
+    local cur_down = (click_action ~= nil) and input.is_action_down(click_action) or false
     local released = (prev_click_down and not cur_down)
     prev_click_down = cur_down
 
+    if not enabled_flag then return end
+    if click_action == nil then return end
+
     local mx, my = engine.input.get_mouse_pos()
 
     if drag_state == "idle" then