feat: Refactor kvstore and vault to use features and logging

- Remove hardcoded dependencies in kvstore Cargo.toml; use features
  instead. This allows for more flexible compilation for different
  targets (native vs. WASM).
- Improve logging in vault crate using the `log` crate. This makes
  debugging easier and provides more informative output during
  execution.  Native tests use `env_logger`, WASM tests use
  `console_log`.
- Update README to reflect new logging best practices.
- Add cfg attributes to native and wasm modules to improve clarity.
- Update traits.rs to specify Send + Sync behavior expectations.

kvstore/Cargo.toml

@@ -8,24 +8,21 @@ path = "src/lib.rs"
 
 [dependencies]
 async-trait = "0.1"
-sled = { version = "0.34", optional = true }
-idb = { version = "0.4", optional = true }
 js-sys = "0.3"
 wasm-bindgen = "0.2"
 wasm-bindgen-futures = "0.4"
 thiserror = "1"
 tempfile = "3"
 
-[features]
-default = []
-native = ["sled", "tokio"]
-web = ["idb"]
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
-tokio = { version = "1.45", optional = true, default-features = false, features = ["rt-multi-thread", "macros"] }
+sled = { version = "0.34" }
+tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-idb = "0.4"
-
-[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+idb = { version = "0.4" }
 wasm-bindgen-test = "0.3"
+
+[features]
+default = []
+native = []