feat(fonts): 后端字体命令 fonts_get_system_fonts 及 ui_font/mono_font 设置字段

apps/app/Cargo.toml

@@ -16,6 +16,7 @@ dashmap = { workspace = true }
 either = { workspace = true }
 enumset = { workspace = true, features = ["serde"] }
 flate2 = { workspace = true }
+fontdb = { workspace = true }
 futures = { workspace = true }
 hyper = { workspace = true, features = ["server"] }
 hyper-util = { workspace = true }