feat: add text glow animation with sinusoidal color cycling and alt-tab bold font rendering

include/client.h

@@ -72,6 +72,7 @@ Client *client_get_last(void);
 
 void client_start_focus_animation(Client *client, bool gaining_focus);
 unsigned long client_get_animated_title_color(Client *client);
+unsigned long client_get_glow_text_color(Client *client);
 void client_update_animations(void);
 
 #endif

include/dwn.h

@@ -95,6 +95,13 @@ typedef struct {
     bool active;
 } ColorAnimation;
 
+typedef struct {
+    float phase;
+    float speed;
+    unsigned long base_color;
+    bool active;
+} TextGlowAnimation;
+
 typedef struct Client Client;
 typedef struct Workspace Workspace;
 typedef struct Monitor Monitor;
@@ -116,6 +123,7 @@ struct Client {
     SnapConstraint snap;
     unsigned long taskbar_color;
     ColorAnimation title_anim;
+    TextGlowAnimation text_glow;
     Client *next;
     Client *prev;
     Client *mru_next;

include/util.h

@@ -58,6 +58,7 @@ unsigned long generate_unique_color(void);
 unsigned long adjust_color_for_background(unsigned long color, unsigned long bg);
 unsigned long interpolate_color(unsigned long from, unsigned long to, float progress);
 unsigned long dim_color(unsigned long color, float factor);
+unsigned long glow_color(unsigned long base, float phase);
 
 long get_time_ms(void);
 void sleep_ms(int ms);