feat: Add SaaS robustness middleware - Rate limiting with token bucket and sliding window algorithms - Input validation (file, language, provider) - Security headers middleware (CSP, XSS protection, etc.) - Automatic file cleanup with TTL tracking - Memory and disk monitoring - Enhanced health check and metrics endpoints - Request logging with unique IDs

middleware/__init__.py

@@ -0,0 +1,62 @@
+"""
+Middleware package for SaaS robustness
+
+This package provides:
+- Rate limiting: Protect against abuse and ensure fair usage
+- Validation: Validate all inputs before processing
+- Security: Security headers, request logging, error handling
+- Cleanup: Automatic file cleanup and resource management
+"""
+
+from .rate_limiting import (
+    RateLimitConfig,
+    RateLimitManager,
+    RateLimitMiddleware,
+    ClientRateLimiter,
+)
+
+from .validation import (
+    ValidationError,
+    ValidationResult,
+    FileValidator,
+    LanguageValidator,
+    ProviderValidator,
+    InputSanitizer,
+)
+
+from .security import (
+    SecurityHeadersMiddleware,
+    RequestLoggingMiddleware,
+    ErrorHandlingMiddleware,
+)
+
+from .cleanup import (
+    FileCleanupManager,
+    MemoryMonitor,
+    HealthChecker,
+    create_cleanup_manager,
+)
+
+__all__ = [
+    # Rate limiting
+    "RateLimitConfig",
+    "RateLimitManager",
+    "RateLimitMiddleware",
+    "ClientRateLimiter",
+    # Validation
+    "ValidationError",
+    "ValidationResult",
+    "FileValidator",
+    "LanguageValidator",
+    "ProviderValidator",
+    "InputSanitizer",
+    # Security
+    "SecurityHeadersMiddleware",
+    "RequestLoggingMiddleware",
+    "ErrorHandlingMiddleware",
+    # Cleanup
+    "FileCleanupManager",
+    "MemoryMonitor",
+    "HealthChecker",
+    "create_cleanup_manager",
+]