Remove Cargo.toml files from el-ui — vessels use manifest.el

All package management is through manifest.el / epm. Cargo.toml files
were incorrectly added to vessels and the root. Removed root workspace
Cargo.toml + Cargo.lock and all vessel-level Cargo.toml files.

el-graph and el-html were already correct (no Cargo.toml).

ui/vessels/el-identity/Cargo.toml

@@ -1,22 +0,0 @@
-[package]
-name = "el-identity"
-version = "0.1.0"
-edition = "2021"
-description = "el-ui Engram-native identity — users, roles, scopes, OAuth, and sessions as graph nodes"
-license = "MIT"
-
-[lib]
-name = "el_identity"
-path = "src/lib.rs"
-
-[dependencies]
-thiserror = "1"
-serde = { version = "1", features = ["derive"] }
-serde_json = "1"
-uuid = { version = "1", features = ["v4", "serde"] }
-chrono = { version = "0.4", features = ["serde"] }
-base64 = "0.22"
-hmac = "0.12"
-sha2 = "0.10"
-
-[dev-dependencies]