Make retry handlers static methods

Convert handle_network_failure and handle_download_failure from instance methods to static methods. Hardcode retry params (max_retries, delays) instead of using instance state. Improves testability and removes implicit dependencies.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/server/error_handler.py

@@ -74,22 +74,28 @@ class RecoveryStrategies:
         delay = self.base_delay * (self.exponential_base ** attempt)
         return min(delay, self.max_delay)
 
+    @staticmethod
     def handle_network_failure(
-        self,
         func: Callable, *args: Any, **kwargs: Any
     ) -> Any:
         """Handle network failures with exponential backoff retry logic."""
         last_error: Optional[Exception] = None
-        for attempt in range(self.max_retries):
+        max_retries = 3
+        base_delay = 1.0
+        max_delay = 60.0
+        exponential_base = 2.0
+        
+        for attempt in range(max_retries):
             try:
                 return func(*args, **kwargs)
             except (NetworkError, ConnectionError, TimeoutError) as exc:
                 last_error = exc
-                if attempt < self.max_retries - 1:
-                    delay = self._calculate_delay(attempt)
+                if attempt < max_retries - 1:
+                    delay = base_delay * (exponential_base ** attempt)
+                    delay = min(delay, max_delay)
                     logger.warning(
                         "Network error on attempt %d/%d, retrying in %.1fs: %s",
-                        attempt + 1, self.max_retries, delay, exc
+                        attempt + 1, max_retries, delay, exc
                     )
                     import time
                     time.sleep(delay)
@@ -98,22 +104,28 @@ class RecoveryStrategies:
             raise last_error
         raise NetworkError("Network failure after retries")
 
+    @staticmethod
     def handle_download_failure(
-        self,
         func: Callable, *args: Any, **kwargs: Any
     ) -> Any:
         """Handle download failures with exponential backoff retry logic."""
         last_error: Optional[Exception] = None
-        for attempt in range(self.max_retries):
+        max_retries = 2
+        base_delay = 1.0
+        max_delay = 60.0
+        exponential_base = 2.0
+        
+        for attempt in range(max_retries):
             try:
                 return func(*args, **kwargs)
             except DownloadError as exc:
                 last_error = exc
-                if attempt < self.max_retries - 1:
-                    delay = self._calculate_delay(attempt)
+                if attempt < max_retries - 1:
+                    delay = base_delay * (exponential_base ** attempt)
+                    delay = min(delay, max_delay)
                     logger.warning(
                         "Download error on attempt %d/%d, retrying in %.1fs: %s",
-                        attempt + 1, self.max_retries, delay, exc
+                        attempt + 1, max_retries, delay, exc
                     )
                     import time
                     time.sleep(delay)