Salvor CLI: run, resume, list, history, and replay --dry-run over durable agent runs.

This library holds the CLI's logic so it can be unit-tested directly (the TOML schema, the rendering) while main stays a thin shell that parses arguments, sets up tracing, and dispatches. The modules split by concern:

• [cli] is the clap parse tree.
• [agent_config] is the TOML agent-definition schema and the mapping into a live [salvor_runtime::Agent].
• [commands] is one handler per verb, wiring [salvor_runtime] and [salvor_store] together.
• [render] is pure value-to-text formatting, shared by the commands.
• [serve_kill] is the process discovery and termination behind salvor serve --kill, kept separate from [commands::serve] because it has nothing to do with actually serving.
• [checkout] is the salvor-checkout detection and login-shell subprocess helper shared by salvor build and salvor serve --dev.
• [dev_server] is the Angular dev server (ng serve) lifecycle behind salvor serve --dev's hot reload.

Where the durability comes from

Nothing here reimplements the runtime. The CLI is a thin operator surface over salvor-runtime: run maps to Runtime::start, and resume maps to either Runtime::resume (a parked run) or Runtime::recover (a crashed one), chosen by folding the recorded log with derive_state. The kill/resume guarantee is the runtime's; the CLI only exposes it.