feat(project): Establish initial IRTT workspace and protocol definitions

Set up the multi-crate project structure and add the core IRTT protocol with pinned dependencies for reproducible builds.

crates/irtt-cli/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "irtt-cli"
+version = "0.1.0"
+edition.workspace = true
+license.workspace = true
+rust-version.workspace = true
+
+[dependencies]

crates/irtt-cli/src/main.rs

@@ -0,0 +1 @@
+fn main() {}