fix(blocks): add limits to loop block to prevent disk exhaustion

- n_loops: max 10 loops
- duration: max 1 hour (3600s)

Prevents DoS via unbounded video generation.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

autogpt_platform/backend/backend/blocks/video/loop.py

@@ -29,11 +29,13 @@ class LoopVideoBlock(Block):
             description="Target duration (in seconds) to loop the video to. If omitted, defaults to no looping.",
             default=None,
             ge=0.0,
+            le=3600.0,  # Max 1 hour to prevent disk exhaustion
         )
         n_loops: Optional[int] = SchemaField(
             description="Number of times to repeat the video. If omitted, defaults to 1 (no repeat).",
             default=None,
             ge=1,
+            le=10,  # Max 10 loops to prevent disk exhaustion
         )
 
     class Output(BlockSchemaOutput):