Replace Slint UI with UIKit and add milestones

Fixes #2.\nFixes #9.

ios/build_rust_core.bash

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+export PATH="/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:$PATH:$HOME/.cargo/bin"
+export RUSTC="$(rustup which --toolchain stable rustc)"
+export RUSTDOC="$(rustup which --toolchain stable rustdoc)"
+export CARGO_TARGET_DIR="$DERIVED_FILE_DIR/cargo"
+
+if [[ "$CONFIGURATION" == "Debug" ]]; then
+    profile=debug
+else
+    profile=release
+fi
+
+libraries=()
+for arch in $ARCHS; do
+    if [[ "$arch" == "arm64" && "${LLVM_TARGET_TRIPLE_SUFFIX:-}" == "-simulator" ]]; then
+        target=aarch64-apple-ios-sim
+    elif [[ "$arch" == "arm64" ]]; then
+        target=aarch64-apple-ios
+    elif [[ "$arch" == "x86_64" ]]; then
+        target=x86_64-apple-ios
+    else
+        echo "Unsupported iOS architecture: $arch" >&2
+        exit 1
+    fi
+
+    if [[ "$profile" == "debug" ]]; then
+        rustup run stable cargo build --locked --target "$target" --package gotcha-app --lib
+    else
+        rustup run stable cargo build --locked --release --target "$target" --package gotcha-app --lib
+    fi
+    libraries+=("$CARGO_TARGET_DIR/$target/$profile/libgotcha_core.a")
+done
+
+mkdir -p "$DERIVED_FILE_DIR/rust"
+lipo -create -output "$DERIVED_FILE_DIR/rust/libgotcha_core.a" "${libraries[@]}"