feat: initial implementation of content-addressed incremental backup engine

Rust-centric architecture with TypeScript facade following smartproxy/smartstorage pattern.
Core engine in Rust (FastCDC chunking, SHA-256, gzip, AES-256-GCM + Argon2id, binary pack files,
global index, snapshots, locking, verification, pruning, repair). TypeScript provides npm interface
via @push.rocks/smartrust RustBridge IPC with Unix socket streaming for ingest/restore.
All 14 integration tests pass.

rust/Cargo.toml

@@ -0,0 +1,47 @@
+[package]
+name = "containerarchive"
+version = "0.1.0"
+edition = "2021"
+
+[[bin]]
+name = "containerarchive"
+path = "src/main.rs"
+
+[dependencies]
+# Async runtime
+tokio = { version = "1", features = ["full"] }
+
+# Serialization
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+
+# CLI
+clap = { version = "4", features = ["derive"] }
+
+# Cryptography
+sha2 = "0.10"
+aes-gcm = "0.10"
+argon2 = "0.5"
+
+# Compression
+flate2 = "1"
+
+# Utilities
+uuid = { version = "1", features = ["v4"] }
+chrono = { version = "0.4", features = ["serde"] }
+hex = "0.4"
+rand = "0.8"
+byteorder = "1"
+
+# Error handling
+thiserror = "2"
+anyhow = "1"
+
+# Logging
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+
+[profile.release]
+opt-level = 3
+lto = true
+strip = true