fix: link current SDK for native window decorations

Makefile

@@ -3,9 +3,11 @@
 APP := .build/Conjure.app
 INSTALL_DIR ?= /Applications
 CODE_SIGN_IDENTITY ?= -
+# Keep AppKit on the current SDK appearance, not deployment-target compatibility styling.
+PLATFORM_FLAGS := -Xlinker -platform_version -Xlinker macos -Xlinker 14.0 -Xlinker $(shell xcrun --show-sdk-version)
 
 build:
-	swift build -c release
+	swift build -c release $(PLATFORM_FLAGS)
 	mkdir -p $(APP)/Contents/MacOS $(APP)/Contents/Resources
 	cp .build/release/Conjure $(APP)/Contents/MacOS/Conjure
 	cp Resources/Info.plist $(APP)/Contents/Info.plist
@@ -21,4 +23,4 @@ install: build
 	swift Scripts/install.swift "$(APP)" "$(INSTALL_DIR)"
 
 test:
-	swift test
+	swift test $(PLATFORM_FLAGS)