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/Cargo.toml

@@ -0,0 +1,19 @@
+[workspace]
+members = ["crates/*"]
+resolver = "2"
+
+[workspace.package]
+version = "0.1.0"
+edition = "2021"
+license = "MIT"
+publish = false
+
+[workspace.lints.rust]
+unsafe_code = "forbid"
+
+[workspace.lints.clippy]
+all = { level = "warn", priority = -1 }
+pedantic = { level = "warn", priority = -1 }
+module_name_repetitions = "allow"
+missing_panics_doc = "allow"
+missing_errors_doc = "allow"