deps: drop glyphon, use cce-ui's cosmic-text re-export

cce-ui no longer depends on glyphon (a wgpu text renderer whose wgpu-side API
was unreachable once the Vulkan path replaced it) — it depends on cosmic-text
directly and re-exports it. Everything this crate named as `glyphon::` was a
cosmic-text re-export, so it now goes through `cce_ui::cosmic_text` and needs
no text-library dependency of its own. That also makes it impossible to drift
onto a second cosmic-text version: a FontSystem handed to cce-ui must be the
same type.

No behavior change — cosmic-text is pinned to the version glyphon resolved to
(=0.12.1) and shaping was verified identical glyph-for-glyph.

Co-Authored-By: Claude <[email protected]>

 Cargo.toml  | 1 -
 src/main.rs | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index ef0d486..e17d84b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,6 @@ calloop = "0.13.0"
 calloop-wayland-source = "0.3.0"
 wayland-client = { version = "0.31", features = ["system"] }
 xkeysym = "0.2"
-glyphon = "0.8"
 tokio = { version = "1", features = ["full"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
diff --git a/src/main.rs b/src/main.rs
index 9dbb386..2441be9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,7 @@
 mod scroll_region;
 use scroll_region::ScrollRegion;
 use wayland_client::QueueHandle;
-use glyphon::FontSystem;
+use cce_ui::cosmic_text::FontSystem;
 use serde::{Serialize, Deserialize};
 use cce_ui::engine::{Application, EngineState, LogicalPosition, LogicalSize, WindowSettings, LineCap};
 use cce_ui::widget::{