docs(config): clarify metadata and conversion file size limits

- correct unit for metadata_max_filesize to match implementation (MiB)
- wording/clarity including resource impact


Signed-off-by: Josh <josh.t.richards@gmail.com>

config/config.sample.php

@@ -1602,20 +1602,27 @@ $CONFIG = [
 	],
 
 	/**
-	 * Maximum file size for metadata generation.
-	 * If a file exceeds this size, metadata generation will be skipped.
+	 * Maximum file size for file metadata generation.
 	 *
-	 * NOTE: memory equivalent to this size will be used for metadata generation.
+	 * Files larger than this limit will be skipped.
 	 *
-	 * Default: 256 megabytes.
+	 * This limit helps bound resource usage during metadata generation. Actual
+	 * resource usage depends on the active metadata providers and how they
+	 * process files. As a rough guide, memory usage may scale with file size.
+	 *
+	 * Default: 256 MiB.
 	 */
 	'metadata_max_filesize' => 256,
 
 	/**
 	 * Maximum file size for file conversion.
-	 * If a file exceeds this size, the file will not be converted.
 	 *
-	 * Default: 100 MiB
+	 * Files larger than this limit will be skipped.
+	 *
+	 * Raising this limit may increase conversion time, resource usage, and the
+	 * risk of timeouts or conversion failures depending on the provider.
+	 *
+	 * Default: 100 MiB.
 	 */
 	'max_file_conversion_filesize' => 100,