feat: per-attribute preservation flags -p/-t/-o/-g with --no-* negations (protocol 2.22.0)

Split FastSync's single use_metadata bundle into four independent rsync-parity attributes: preserve_perms, preserve_times, preserve_owner, preserve_group. use_metadata is now a derived transport bit (config_derived_use_metadata).

CLI: real -p/--perms, -t/--times, -o/--owner, -g/--group plus --no-perms/--no-times/--no-owner/--no-group (short and long) and --no-preserve; -a is now rsync -rlptgoD; --preserve = -pt; -A implies -p; -X does not; --chmod implies -p; --usermap/--groupmap/--chown imply owner/group per side; --incremental/--delta still auto-preserve unless negated.

Receiver: per-attribute FileAttrPolicy gating for files, dirs (modes applied at end of transfer), symlinks and specials; rsync -E read-bit rule; new files get source_mode & ~umask sanitized (no group/other write); per-side identity resolution; deferred directory metadata; batch dir-metadata replay; daemon modules without 'client owner = yes' no longer refuse plain -a but force super off (no ownership) with a warning.

Wire: PROTOCOL_VERSION 2.21.0 -> 2.22.0 (four appended config bools, golden 653 / 95530566005420798). FileMetadata/chunk/batch framing unchanged. Docs/CHANGELOG/CMake updated to 2.22.0.

tests/integration/test_preflight.py

@@ -94,14 +94,14 @@ def _seed_protocol_source(source):
 class TestProtocol:
     @pytest.mark.ci
     def test_protocol_current_version_accepted(self, shared_server):
-        """--protocol=2.21.0 (the current PROTOCOL_VERSION) is accepted and the
+        """--protocol=2.22.0 (the current PROTOCOL_VERSION) is accepted and the
         transfer completes normally."""
         source = os.path.join(TEST_DATA_DIR, "proto_ok_src")
         dest = os.path.join(TEST_DATA_DIR, "proto_ok_dst")
         shutil.rmtree(dest, ignore_errors=True)
         os.makedirs(dest)
         _seed_protocol_source(source)
-        result, _ = run_client(source, dest, flags=["--protocol=2.21.0"],
+        result, _ = run_client(source, dest, flags=["--protocol=2.22.0"],
                                port=shared_server.port)
         assert result.returncode == 0, \
             f"--protocol current run failed: {(result.stderr or result.stdout)[:400]}"
@@ -118,7 +118,8 @@ class TestProtocol:
         shutil.rmtree(dest, ignore_errors=True)
         os.makedirs(dest)
         _seed_protocol_source(source)
-        for bad in ("2.20.0", "2.19.0", "2.18.0", "2.17.0", "2.15.0", "2.16.0", "216", "31"):
+        for bad in ("2.21.0", "2.20.0", "2.19.0", "2.18.0", "2.17.0", "2.15.0", "2.16.0", "216",
+                    "31"):
             result, _ = run_client(source, dest, flags=[f"--protocol={bad}"],
                                    port=shared_server.port)
             assert result.returncode != 0, f"--protocol={bad} should be rejected"