Initial workspace scaffold

Cargo workspace with 5 crates: buh-entity (pure data structs),
buh-data (Turso/libsql data access), buh-util (scraper, rules,
processor, sync modules), buh-cli (binary "buh" with client/daemon
subcommands), and buh-ws (axum WebSocket server).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -0,0 +1,40 @@
+[workspace]
+resolver = "3"
+members = ["crates/*"]
+
+[workspace.package]
+edition = "2024"
+version = "0.1.0"
+license = "MIT"
+
+[workspace.dependencies]
+# internal
+buh-entity = { path = "crates/buh-entity" }
+buh-data = { path = "crates/buh-data" }
+buh-util = { path = "crates/buh-util" }
+
+# async runtime
+tokio = { version = "1", features = ["full"] }
+
+# serialization
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+toml = "0.8"
+
+# http / websocket
+reqwest = { version = "0.12", features = ["json"] }
+axum = { version = "0.8", features = ["ws"] }
+
+# database
+libsql = "0.9"
+
+# cli
+clap = { version = "4", features = ["derive"] }
+
+# observability
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+
+# errors
+thiserror = "2"
+anyhow = "1"