feat(init): scaffold cargo workspace and CI

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

Cargo.toml

@@ -0,0 +1,24 @@
+[workspace]
+resolver = "2"
+members = ["crates/core", "crates/gui", "crates/tui"]
+default-members = ["crates/core"]
+
+[workspace.dependencies]
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+thiserror = "2"
+parking_lot = "0.12"
+crossbeam-channel = "0.5"
+notify = "8"
+regex = "1"
+memchr = "2"
+toml = "0.8"
+directories = "6"
+insta = "1"
+anyhow = "1"
+egui = "0.34"
+eframe = "0.34"
+ratatui = "0.30"
+crossterm = "0.29"
+clap = { version = "4", features = ["derive"] }
+log-viewer-core = { path = "crates/core" }