Merge develop into claude/fix-issue-3989-db7e45

Resolve the conflict in binary_reader.hpp: develop dropped the
document_size < 0 check in check_bson_document_size(), because sizes below 5
are rejected before they are stored. Here such a size is only stored after it
was repaired, and the !size_repaired guard skips the check, so the check is
dropped here as well. Regenerate the single headers.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEVkSyiaFoX2FtPpsU

docs/mkdocs/mkdocs.yml

@@ -130,6 +130,7 @@ nav:
           - features/element_access/unchecked_access.md
           - features/element_access/checked_access.md
           - features/element_access/default_value.md
+      - features/files.md
       - features/iterators.md
       - features/merge_patch.md
       - features/json_patch.md