feat(parity): rsync 3.4.1 checksum/timeout/temp-dir/connectivity parity (#289 #295 #296)

#289 checksum/compression:
- -c/--checksum now implies the incremental content quick-check (without
  implying -t), so an unchanged file is skipped like rsync.
- --checksum-choice/--cc accepts xxh64/xxhash, xxh3, xxh128, md5 and auto;
  md4/sha1/none and the two-name form are rejected by name.
- --compress-choice/--zc rejects lz4/zlib/zlibx by name (zstd/none/auto kept).
- --checksum-seed=0 is randomized per transfer and sent on the wire.
- --skip-compress uses rsync 3.4.1's default suffix list; slash separators and
  dot-less suffixes are accepted.
- add --no-whole-file.

#295 timeouts/alloc/temp-dir:
- --timeout default 0 (disabled), --contimeout default 60; 0 disables both,
  plus --no-timeout/--no-contimeout.
- --max-alloc=0 means no allocation limit (was rejected).
- --temp-dir accepts any dir, requires it to exist, and falls back to a
  non-atomic copy on EXDEV instead of aborting.

#296 connectivity/daemon:
- -M/--remote-option is rejected for daemon/TCP destinations (SSH-only).
- --trust-sender clarified as receiver-local; server-path tests added.
- --stop-at accepts rsync's full date form (y-m-dTh:m etc.).

Adds unit and integration coverage; no wire-field change, PROTOCOL_VERSION stays
2.22.0.

tests/test_compression.c

@@ -64,6 +64,21 @@ static void test_skip_compress_suffix_matching() {
   EXPECT_TRUE(compression_should_skip_with_suffixes("backup.TAR.GZ", suffixes, 2));
   EXPECT_FALSE(compression_should_skip_with_suffixes("notes.txt", suffixes, 2));
   EXPECT_FALSE(compression_should_skip_with_suffixes("archive.zip", suffixes, 0));
+
+  /* A user suffix may omit the leading dot (rsync's spelling). */
+  char* bare[] = {"zip", "gz"};
+  EXPECT_TRUE(compression_should_skip_with_suffixes("archive.zip", bare, 2));
+  EXPECT_TRUE(compression_should_skip_with_suffixes("x.GZ", bare, 2));
+
+  /* No user list (count < 0) selects rsync 3.4.1's built-in default list. */
+  EXPECT_TRUE(compression_should_skip_with_suffixes("movie.mp4", NULL, -1));
+  EXPECT_TRUE(compression_should_skip_with_suffixes("archive.TAR.GZ", NULL, -1));
+  EXPECT_TRUE(compression_should_skip_with_suffixes("photo.jpeg", NULL, -1));
+  EXPECT_TRUE(compression_should_skip_with_suffixes("disk.squashfs", NULL, -1));
+  EXPECT_TRUE(compression_should_skip_with_suffixes("data.7z", NULL, -1));
+  EXPECT_FALSE(compression_should_skip_with_suffixes("notes.txt", NULL, -1));
+  EXPECT_FALSE(compression_should_skip_with_suffixes("program", NULL, -1));
+  EXPECT_FALSE(compression_should_skip_with_suffixes("trailing.", NULL, -1));
 }
 
 static void test_data_compress_with_threads_roundtrip() {