Build secure Rust watchOS TOTP core (#56)

apple/project.yml

@@ -77,6 +77,10 @@ targets:
       PRODUCT_BUNDLE_IDENTIFIER: de.rfc1437.ironstorage.watch
       PRODUCT_NAME: IronStorage Watch
       SKIP_INSTALL: YES
+      "EXCLUDED_ARCHS[sdk=watchsimulator*]": x86_64
+      SWIFT_OBJC_BRIDGING_HEADER: IronStorage-Watch-Bridging-Header.h
+      LIBRARY_SEARCH_PATHS: "$(inherited) $(DERIVED_FILE_DIR)/rust"
+      OTHER_LDFLAGS: "$(inherited) -lironstorage_watch"
     info:
       path: Watch-Info.plist
       properties:
@@ -86,3 +90,11 @@ targets:
     sources:
       - Assets.xcassets
       - Sources/Watch
+      - Generated/ironstorage_watch.swift
+    preBuildScripts:
+      - name: Build Rust Watch core
+        basedOnDependencyAnalysis: false
+        script: |
+          ./build_rust_core.bash
+        outputFiles:
+          - $(DERIVED_FILE_DIR)/rust/libironstorage_watch.a