v2.0: dual deployment — pip install (SQLite) + Docker (PostgreSQL)

Architecture:
- Moved backend/app/ to diligence/ Python package
- Dialect-agnostic models (Uuid + JSON, no PostgreSQL imports)
- Auto-detect database: empty DATABASE_URL → SQLite at ~/.diligence/data.db
- Cross-dialect migrations (inspector-based, no raw PostgreSQL DDL)
- FastAPI serves pre-built React frontend for pip path
- CLI entry point: diligence [--port] [--no-browser] [--data-dir]
- pyproject.toml with optional deps: [postgres], [mcp], [dev]
- Docker path unchanged: docker compose up -d

pip install path: pip install . && diligence
Docker path: ./setup.sh && docker compose up -d

pyproject.toml

@@ -0,0 +1,65 @@
+[build-system]
+requires = ["setuptools>=68.0", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "diligence"
+version = "2.0.0"
+description = "Self-hosted fitness rewards platform with AI agent integration"
+readme = "README.md"
+license = {text = "MIT"}
+requires-python = ">=3.11"
+authors = [
+    {name = "DiligenceWorks Pte. Ltd.", email = "hello@diligenceworks.online"},
+]
+keywords = ["fitness", "self-hosted", "mcp", "ai-agent", "rewards"]
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "License :: OSI Approved :: MIT License",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Topic :: Internet :: WWW/HTTP :: WSGI :: Application",
+]
+
+dependencies = [
+    "fastapi>=0.115.0",
+    "uvicorn[standard]>=0.30.0",
+    "sqlalchemy[asyncio]>=2.0.30",
+    "aiosqlite>=0.20.0",
+    "pydantic>=2.10.0",
+    "pydantic-settings>=2.7.0",
+    "python-jose[cryptography]>=3.3.0",
+    "bcrypt>=4.2.0",
+    "httpx>=0.27.0",
+    "python-multipart>=0.0.18",
+]
+
+[project.optional-dependencies]
+postgres = [
+    "asyncpg>=0.30.0",
+]
+mcp = [
+    "mcp[cli]>=1.0.0",
+]
+dev = [
+    "pytest>=8.0",
+    "pytest-asyncio>=0.23",
+    "ruff>=0.8.0",
+]
+
+[project.scripts]
+diligence = "diligence.cli:main"
+
+[project.urls]
+Homepage = "https://github.com/DiligenceWorks/Diligence"
+Documentation = "https://github.com/DiligenceWorks/Diligence#readme"
+Repository = "https://github.com/DiligenceWorks/Diligence"
+Issues = "https://github.com/DiligenceWorks/Diligence/issues"
+
+[tool.setuptools.packages.find]
+include = ["diligence*"]
+
+[tool.setuptools.package-data]
+diligence = ["frontend/**/*"]