feat: Rust port of Claude Code CLI

Crates:
- api: Anthropic Messages API client with SSE streaming
- tools: Claude-compatible tool implementations (Bash, Read, Write, Edit, Glob, Grep + extended suite)
- runtime: conversation loop, session persistence, permissions, system prompt builder
- rusty-claude-cli: terminal UI with markdown rendering, syntax highlighting, spinners
- commands: subcommand definitions
- compat-harness: upstream TS parity verification

All crates pass cargo fmt/clippy/test.

rust/crates/compat-harness/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "compat-harness"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+commands = { path = "../commands" }
+tools = { path = "../tools" }
+runtime = { path = "../runtime" }
+
+[lints]
+workspace = true