docs(parity): finalize rsync-parity docs for protocol 2.26.0

Reclassify the RSYNC_COMPAT matrix after the parity-completion wave (protocol
2.23.0 -> 2.26.0): 9 already-parity rows to parity, 17 inherently non-rsync
rows to divergent, and the genuine fixes to parity, recounting to
109 parity / 25 caveat / 23 divergent of 157 rows. Add rows for --bwlimit,
--partial, --partial-dir, --no-whole-file, --inc-recursive/--no-inc-recursive,
--protect-args and --msgs2stderr; fix the documented -f/filter, -F/.rsync-filter,
empty --files-from, and --preallocate/--sparse precedence bugs; add the Parity
Completion Wave section.

Refresh README/HANDOFF/release skill/cmake-expert to protocol 2.26.0 and the
zlib/lz4 + md4/sha1/none codecs, add the CHANGELOG 2.26.0 entry, and correct
the stale --max-delete --help wording.

.opencode/skills/release/SKILL.md

@@ -16,7 +16,7 @@ Ask the user or determine from context:
 - **Minor** (x.Y.0) — new features, backward compatible
 - **Patch** (x.y.Z) — bug fixes, no protocol changes
 
-Current version: `PROTOCOL_VERSION "2.23.0"` in `src/shared/config.h`
+Current version: `PROTOCOL_VERSION "2.26.0"` in `src/shared/config.h`
 
 ### Step 2: Check Protocol Version