Add initial project structure and documentation

- Created architecture documentation outlining high-level design, module organization, data flow, security model, performance considerations, testing strategy, and deployment architecture.
- Added pyproject.toml for project metadata and dependencies management.
- Introduced requirements files for development and production dependencies.
- Set up testing configuration with pytest and tox.
- Established basic directory structure for source code and tests, including __init__.py files.
- Implemented a sample web application (index.html) for drag-and-drop functionality.
- Configured VS Code workspace settings for Python development.

Makefile

@@ -0,0 +1,82 @@
+.PHONY: help install install-dev test lint format type clean build-windows build-macos docs
+
+help:
+	@echo "WebDrop Bridge - Development Commands"
+	@echo "======================================"
+	@echo ""
+	@echo "Setup:"
+	@echo "  make install           Install production dependencies"
+	@echo "  make install-dev       Install development dependencies"
+	@echo ""
+	@echo "Testing:"
+	@echo "  make test              Run all tests with coverage"
+	@echo "  make test-quick        Run tests without coverage"
+	@echo "  make test-unit         Run unit tests only"
+	@echo "  make test-integration  Run integration tests only"
+	@echo ""
+	@echo "Code Quality:"
+	@echo "  make lint              Run linting checks (ruff, black)"
+	@echo "  make format            Auto-format code (black, isort)"
+	@echo "  make type              Run type checking (mypy)"
+	@echo "  make quality           Run all quality checks (lint, type, test)"
+	@echo ""
+	@echo "Building:"
+	@echo "  make build-windows     Build Windows executable"
+	@echo "  make build-macos       Build macOS DMG"
+	@echo "  make clean             Remove build artifacts"
+	@echo ""
+	@echo "Documentation:"
+	@echo "  make docs              Build Sphinx documentation"
+	@echo ""
+
+install:
+	pip install -r requirements.txt
+
+install-dev:
+	pip install -r requirements-dev.txt
+
+test:
+	pytest tests -v --cov=src/webdrop_bridge --cov-report=html
+
+test-quick:
+	pytest tests -v
+
+test-unit:
+	pytest tests/unit -v
+
+test-integration:
+	pytest tests/integration -v
+
+lint:
+	ruff check src tests
+	black --check src tests
+	isort --check-only src tests
+
+format:
+	black src tests
+	isort src tests
+	ruff check --fix src tests
+
+type:
+	mypy src/webdrop_bridge
+
+quality: lint type test
+
+clean:
+	rm -rf build/dist build/temp build/specs
+	rm -rf htmlcov .coverage .pytest_cache
+	rm -rf .mypy_cache .ruff_cache
+	find . -type d -name __pycache__ -exec rm -rf {} +
+	find . -type f -name "*.pyc" -delete
+	find . -type f -name "*.pyo" -delete
+
+build-windows:
+	python build/scripts/build_windows.py
+
+build-macos:
+	bash build/scripts/build_macos.sh
+
+docs:
+	cd docs && sphinx-build -W -b html -d _build/doctrees . _build/html
+
+.DEFAULT_GOAL := help