Add development mode with automatic test data seeding

- Add ORCHARD_ENV setting (defaults to 'development')
- Add seed.py with test projects, packages, artifacts, and tags
- Automatically seed database on startup in development mode
- Skip seeding if database already contains data
- Skip seeding in production mode (ORCHARD_ENV=production)

Test data includes:
- 4 projects (3 public, 1 private)
- 8 packages across projects
- 5 artifacts with various content types
- 10 tags including version tags and 'latest'

backend/app/main.py

@@ -2,19 +2,35 @@ from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 from fastapi.responses import FileResponse
 from contextlib import asynccontextmanager
+import logging
 import os
 
 from .config import get_settings
-from .database import init_db
+from .database import init_db, SessionLocal
 from .routes import router
+from .seed import seed_database
 
 settings = get_settings()
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
 
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     # Startup: initialize database
     init_db()
+
+    # Seed test data in development mode
+    if settings.is_development:
+        logger.info(f"Running in {settings.env} mode - checking for seed data")
+        db = SessionLocal()
+        try:
+            seed_database(db)
+        finally:
+            db.close()
+    else:
+        logger.info(f"Running in {settings.env} mode - skipping seed data")
+
     yield
     # Shutdown: cleanup if needed