feat: bar 点击回调添加按键和修饰键参数

on_click 新增 modifiers/button，使 bar item 可按按键与修饰键区分动作；
因参数增多，回调与 bar_click 改用结构参数封装。同时将 button_t 与
modifier 类型提升至公开头 include/zdwm/types.h 以供使用

include/zdwm/bar.h

@@ -59,6 +59,15 @@ typedef struct zdwm_bar_cell_api_t {
   void (*cell_set_indicator)(zdwm_bar_item_t *item, size_t index, bool show);
 } zdwm_bar_cell_api_t;
 
+typedef struct zdwm_bar_click_params_t {
+  zdwm_bar_item_t *item;
+  size_t cell_index;
+  int32_t x;
+  zdwm_modifier_mask_t modifiers;
+  zdwm_button_t button;
+  void *state;
+} zdwm_bar_click_params_t;
+
 typedef struct zdwm_bar_item_type_t {
   void *(*create_state)(zdwm_output_id_t output_id, void *config);
   void (*update)(
@@ -66,12 +75,7 @@ typedef struct zdwm_bar_item_type_t {
     const zdwm_bar_cell_api_t *cells,
     void *state
   );
-  zdwm_action_t (*on_click)(
-    zdwm_bar_item_t *item,
-    size_t cell_index,
-    int32_t x,
-    void *state
-  );
+  zdwm_action_t (*on_click)(zdwm_bar_click_params_t *params);
   void (*destroy_state)(void *state);
   zdwm_bar_item_t *instance;
   uint32_t update_interval_ms;

include/zdwm/types.h

@@ -18,6 +18,25 @@ typedef uint32_t zdwm_binding_mode_id_t;
 #define ZDWM_WORKSPACE_ID_INVALID    ((zdwm_workspace_id_t)UINT32_MAX)
 #define ZDWM_BINDING_MODE_ID_INVALID ((zdwm_binding_mode_id_t)UINT32_MAX)
 
+typedef enum zdwm_button_t {
+  ZDWM_BUTTON_NONE,
+  ZDWM_BUTTON_LEFT,
+  ZDWM_BUTTON_RIGHT,
+  ZDWM_BUTTON_MIDDLE,
+} zdwm_button_t;
+
+typedef enum zdwm_modifier_bit_t {
+  ZDWM_MOD_NONE    = 0u,
+  ZDWM_MOD_SHIFT   = 1u << 0,
+  ZDWM_MOD_CONTROL = 1u << 1,
+  ZDWM_MOD_1       = 1u << 2,
+  ZDWM_MOD_2       = 1u << 3,
+  ZDWM_MOD_3       = 1u << 4,
+  ZDWM_MOD_4       = 1u << 5,
+  ZDWM_MOD_5       = 1u << 6,
+} zdwm_modifier_bit_t;
+typedef uint32_t zdwm_modifier_mask_t;
+
 typedef struct zdwm_rect_t {
   int32_t x;
   int32_t y;