docs(phase-1): rewrite reference pages (api, cli, configuration)

Part of #224 — v2 docs rewrite (Diátaxis).

## Goal

`reference/api.md` and `reference/cli.md` (incl. configuration) complete, neutral, and verified — the substrate every other page links to.

## Tasks

- [x] api.md: split into Methods (25), Schemas, Enums, Error codes
- [x] api.md: strip Quickstart & Game States into their new homes (walkthrough → write-a-bot.md; state model → explanation/game-state.md)
- [x] api.md: verify each method against openrpc.json + its endpoint Lua file; live-replay all examples
- [x] cli.md: keep only command/option/env-var reference (incl. configuration section: settings profiles, balatrobot.json, env vars)
- [x] cli.md: verify against typer help output, config.py + lua profiles

## Dependencies

- Blocked by: #225 (Phase 0 — audit & scaffold)
- Blocks: Phase 2 (explanation), Phase 3 (how-to), Phase 4 (automation), Phase 5 (ship)

## Done when

- [x] Every openrpc method/param/schema/enum present and accurate in api.md
- [x] Every typer option documented in cli.md
- [x] All examples replayed against a live Balatro instance

Start by checking the completed task and done checklists in this issue; they indicate the requested work may already be finished. If anything remains, compare reference/api.md with openrpc.json and its endpoint Lua files, and reference/cli.md with typer help output, config.py, and Lua profiles. Done means the references are complete, accurate, and the examples replay successfully against a live Balatro instance.

Written by the indexing model from the issue text.