Restructure for multi-platform support and add Settings UI

- Move macOS code to macos/ directory for platform separation
- Add Settings window with configurable language, model path, and sound toggle
- Add launch at login support using SMAppService
- Add proper .app bundle structure with Info.plist
- Add Makefile for build, install, run, and dmg targets
- Store preferences in UserDefaults for persistence

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

macos/Makefile

@@ -0,0 +1,51 @@
+# WhisperDictate macOS Build
+
+APP_NAME = WhisperDictate
+APP_BUNDLE = $(APP_NAME).app
+VERSION = 1.0.0
+
+# Directories
+SRC_DIR = src
+BUILD_DIR = build
+BUNDLE_DIR = $(APP_BUNDLE)/Contents
+
+# Compiler settings
+SWIFT = swiftc
+SWIFT_FLAGS = -O -framework Cocoa -framework AVFoundation -framework Carbon -framework CoreGraphics -framework ServiceManagement
+
+.PHONY: all clean build install run dmg
+
+all: build
+
+build: $(BUILD_DIR)/$(APP_NAME)
+	@echo "✓ Build complete"
+
+$(BUILD_DIR)/$(APP_NAME): $(SRC_DIR)/main.swift
+	@mkdir -p $(BUILD_DIR)
+	@mkdir -p $(BUNDLE_DIR)/MacOS
+	@mkdir -p $(BUNDLE_DIR)/Resources
+	$(SWIFT) $(SWIFT_FLAGS) -o $(BUNDLE_DIR)/MacOS/$(APP_NAME) $(SRC_DIR)/main.swift
+	@cp $(APP_BUNDLE)/Contents/Info.plist $(BUNDLE_DIR)/ 2>/dev/null || true
+	@touch $(BUILD_DIR)/$(APP_NAME)
+	@echo "✓ Built $(APP_BUNDLE)"
+
+clean:
+	rm -rf $(BUILD_DIR)
+	rm -rf $(BUNDLE_DIR)/MacOS/$(APP_NAME)
+	@echo "✓ Cleaned"
+
+install: build
+	@rm -rf /Applications/$(APP_BUNDLE)
+	@cp -R $(APP_BUNDLE) /Applications/
+	@codesign --force --deep --sign - /Applications/$(APP_BUNDLE)
+	@echo "✓ Installed to /Applications/$(APP_BUNDLE)"
+
+run: build
+	@./$(BUNDLE_DIR)/MacOS/$(APP_NAME) &
+	@echo "✓ Running $(APP_NAME)"
+
+dmg: build
+	@rm -f $(APP_NAME)-$(VERSION).dmg
+	@codesign --force --deep --sign - $(APP_BUNDLE)
+	@hdiutil create -volname "$(APP_NAME)" -srcfolder $(APP_BUNDLE) -ov -format UDZO $(APP_NAME)-$(VERSION).dmg
+	@echo "✓ Created $(APP_NAME)-$(VERSION).dmg"