fix: revert messageHasContentFromSDK unknown type handling

Unknown part types should be treated as content (return true)
to match parity with the existing message-builder implementation.
Using continue would incorrectly mark messages with unknown part
types as empty, triggering false recovery.

src/hooks/anthropic-context-window-limit-recovery/empty-content-recovery-sdk.ts

@@ -32,7 +32,7 @@ function messageHasContentFromSDK(message: SDKMessage): boolean {
 
     if (TOOL_TYPES.has(type)) return true
 
-    continue
+    return true
   }
 
   return false