chore: cargo workspace with citygen and city crates

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Cargo.toml

@@ -0,0 +1,29 @@
+[workspace]
+resolver = "3"
+members = ["crates/citygen", "crates/city"]
+
+[workspace.package]
+edition = "2024"
+version = "0.1.0"
+license = "MIT"
+
+[workspace.dependencies]
+serde = { version = "1", features = ["derive"] }
+rand = "0.9"
+rand_chacha = "0.9"
+noise = "0.9"
+thiserror = "2"
+anyhow = "1"
+ron = "0.10"
+postcard = { version = "1", features = ["use-std"] }
+serde_json = "1"
+ratatui = "0.29"
+crossterm = "0.28"
+clap = { version = "4", features = ["derive"] }
+unicode-width = "0.2"
+
+[profile.dev]
+opt-level = 1
+
+[profile.release]
+lto = "thin"