refactor: create FontSystem via cce_ui::create_font_system_with_system_fonts

Use the shared cce_ui helper (system + bundled CCE fonts) instead of a bare
glyphon::FontSystem::new(). For the five apps that used FontSystem::new() this
additionally loads the bundled CCE fonts; the two hybrids drop their manual
load_fonts_dir call. Additive — no font source is lost.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

 src/main.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index b631048..e44683c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -706,7 +706,7 @@ impl Application for ColorApp {
             sliders.push(ColorSlider::new("A", 6));
         }
 
-        let font_system = FontSystem::new();
+        let font_system = cce_ui::create_font_system_with_system_fonts();
 
         let mut app = Self {
             root_window,