asset slice + testing initiative: fixed assets, property/mutation/fuzz testing, docs

crates/ledger-store/Cargo.toml

@@ -12,6 +12,7 @@ rusqlite = { version = "0.32", features = ["bundled"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 chrono = "0.4"
+rust_decimal = "1"
 thiserror = "2"
 sha2 = "0.10"
 hex = "0.4"