AFF4: leitura (snappy/deflate/LZ4, mapas esparsos) e gravação; CLI --format aff4

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/guara-core/Cargo.toml

@@ -20,6 +20,9 @@ flate2 = { version = "1", default-features = false, features = ["rust_backend"]
 thiserror = "2"
 tiny_http = "0.12"
 bzip2 = "0.6"
+zip = { version = "2", default-features = false, features = ["deflate"] }
+snap = "1"
+lz4_flex = { version = "0.11", default-features = false, features = ["safe-decode", "safe-encode"] }
 aes = "0.8"
 hmac = "0.12"
 pbkdf2 = { version = "0.12", default-features = false, features = ["hmac"] }