feat(app): register global exception handlers in FastAPI

Update main.py to setup exception handlers during app initialization:
- Import setup_exception_handlers from error_handlers module
- Call setup_exception_handlers(app) after middleware setup

Part of Issue #7: Error Handling & Resilience

Author: Sakeeb91

app/main.py

@@ -11,6 +11,7 @@
 
 from app import __version__
 from app.config import get_settings
+from app.error_handlers import setup_exception_handlers
 from app.logging_config import configure_logging, get_logger
 from app.middleware import setup_middleware
 from app.routes import router
@@ -158,6 +159,9 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
 # Setup middleware
 setup_middleware(app, cors_origins=settings.api.cors_origins_list)
 
+# Setup exception handlers (Phase 2.3: Error Handling & Resilience)
+setup_exception_handlers(app)
+
 # Setup rate limiting (Phase 2.2: Security Implementation)
 setup_rate_limiting(app)