Use document views in file processing and history

Replace broad entry inputs with the information used by file processing,
history, and JSON comparison. Separate customisation content and save-base
results from database-document models, and keep content fields out of
logical-deletion Metadata while preserving the parent revision.

Record the accepted design, compatibility boundaries, and verification.
Requires Commonlib commit 751b29a74340da57122b8ab11b80d00c40272120.
The registry dependency remains at 0.2.3 pending publication and adoption.

updates.md

@@ -14,6 +14,10 @@ Earlier releases remain available in the 1.0 release history, the 1.0 preview hi
 
 ### Fixed
 
+#### File history
+
+- Reading the oldest inline document format by path now retains its content, including when restoring an earlier revision. Both `notes` documents and documents without `type` use the existing text or Base64 interpretation instead of returning empty content.
+
 #### Translations
 
 - The notice shown when a translation is available now displays the **Display Language** setting label correctly in English, French, Hebrew, Russian, and Simplified Chinese. (#1298) Thank you to @cwatanab for the contribution!