Replace Slint UI with UIKit and add milestones

Fixes #2.\nFixes #9.

crates/app/Cargo.toml

@@ -6,18 +6,15 @@ edition.workspace = true
 license.workspace = true
 rust-version.workspace = true
 
-[[bin]]
-name = "gotcha-app"
-path = "src/main.rs"
+[lib]
+name = "gotcha_core"
+crate-type = ["lib", "staticlib"]
 
 [dependencies]
 gotcha_gitea = { path = "../gitea" }
-pulldown-cmark = "0.13"
 serde.workspace = true
 serde_json.workspace = true
 security-framework = "3"
-slint.workspace = true
+thiserror = "2"
 tokio.workspace = true
-
-[build-dependencies]
-slint-build = "=1.17.1"
+uniffi = { version = "0.32", features = ["tokio"] }