Add multi-theme system with random theme selection on app startup

src-tauri/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "countdown"
+version = "0.1.0"
+description = "A Countdown app"
+authors = ["sangge"]
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+# The `_lib` suffix may seem redundant but it is necessary
+# to make the lib name unique and wouldn't conflict with the bin name.
+# This seems to be only an issue on Windows, see https://github.com/rust-lang/cargo/issues/8519
+name = "countdown_lib"
+crate-type = ["staticlib", "cdylib", "rlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+rusqlite = { version = "0.33.0", features = ["bundled"] }
+tauri = { version = "2", features = [] }
+tauri-plugin-opener = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+chrono = "0.4.39"