feat: implement file upload handler and related functionality

- Added file upload handler to process both multipart and raw file uploads.
- Implemented parsing logic for upload requests, including handling file metadata.
- Introduced SaveFileDecodedInput structure for handling decoded file uploads.
- Created unit tests for file upload parsing and validation.

feat: add metadata retry configuration and functionality

- Introduced MetadataRetryConfig to the application configuration.
- Implemented MetadataRetryer to handle retrying metadata extraction for thoughts.
- Added new tool for retrying failed metadata extractions.
- Updated thought metadata structure to include status and timestamps for metadata processing.

fix: enhance metadata normalization and error handling

- Updated metadata normalization functions to track status and errors.
- Improved handling of metadata extraction failures during thought updates and captures.
- Ensured that metadata status is correctly set during various operations.

refactor: streamline file saving logic in FilesTool

- Refactored Save method in FilesTool to utilize new SaveDecoded method.
- Simplified project and thought ID resolution logic during file saving.

internal/config/validate.go

@@ -89,6 +89,11 @@ func (c Config) Validate() error {
 			return fmt.Errorf("invalid config: backfill.max_per_run must be >= backfill.batch_size")
 		}
 	}
+	if c.MetadataRetry.Enabled {
+		if c.MetadataRetry.MaxPerRun <= 0 {
+			return fmt.Errorf("invalid config: metadata_retry.max_per_run must be greater than zero when metadata_retry is enabled")
+		}
+	}
 
 	return nil
 }