Initial commit: Howl M365 email management daemon

Full implementation of the Howl email triage system:
- Microsoft Graph API integration with MSAL auth (client-credentials and delegated modes)
- Claude LLM classification via tool use for structured output
- PostgreSQL database with customers, vendors, whitelist, and email_log tables
- Alembic migration for full schema
- APScheduler daemon with graceful shutdown
- Typer CLI (run, dry-run, status commands)
- Business rule classifier with overrides (whitelist protection, low-confidence fallback)
- Action executor (move to folders, flag, escalate with webhook)
- 35 passing unit tests
- README, SETUP, and NEXT_STEPS documentation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -0,0 +1,57 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "howl"
+version = "0.1.0"
+description = "M365 email management daemon with LLM-powered filtering"
+requires-python = ">=3.11"
+dependencies = [
+    # Microsoft Graph + auth
+    "msal>=1.31.0",
+    "msgraph-sdk>=1.9.0",
+    "httpx>=0.27.0",
+    # Database
+    "sqlalchemy>=2.0.0",
+    "alembic>=1.13.0",
+    "asyncpg>=0.30.0",
+    "psycopg[binary]>=3.2.0",
+    # LLM
+    "anthropic>=0.40.0",
+    # Config & validation
+    "pydantic>=2.9.0",
+    "pydantic-settings>=2.6.0",
+    # CLI
+    "typer>=0.13.0",
+    "rich>=13.0.0",
+    # Scheduling
+    "apscheduler>=3.10.0",
+    # Logging
+    "structlog>=24.0.0",
+    # Retry
+    "tenacity>=9.0.0",
+    # HTML stripping for email bodies
+    "beautifulsoup4>=4.12.0",
+]
+
+[project.scripts]
+howl = "howl.main:app"
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0.0",
+    "pytest-asyncio>=0.24.0",
+    "respx>=0.21.0",
+    "pytest-cov>=5.0.0",
+]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+markers = [
+    "integration: marks tests that require real external services (deselect with '-m not integration')",
+]
+
+[tool.hatch.build.targets.wheel]
+packages = ["howl"]