D23 — Multi-provider configurator: CLI flags + per-provider JSON adapters, non-destructive merge

Decision. The configurator accepts CLI flags (--name, --transport, --url, --auth, --token-env) with sensible defaults (DefaultConfig()) and generates the MCP configuration files for Claude Code (.claude.json, mcpServers key), Codex CLI (.codex/config.json), Kiro (.kiro/settings/mcp.json), and OpenCode (.opencode/config.json). Claude Code reads mcpServers from ~/.claude.json, not from a separate .claude/mcp_servers.json file. Merging with existing files is non-destructive: entries for other servers are preserved. Implemented as the internal/configurator package + the cmd/configure binary. Rationale. CLI flags are the simplest and most composable configuration point — no YAML file to maintain in the KB, no extra parsers. The non-destructive merge is essential to avoid overwriting the user's existing configurations. The JSON format uses stdlib encoding/json. The mcp/wiki.yaml (previously the source of truth) was removed together with the mcp/ and raw/ directories from the KB structure (June 2026, D28). (Superseded by D37: cmd/configure was deleted — the client subcommands now live in cmd/cartographer, HTTP-only transport.) (Bug discovered in D58: .codex/config.json was never the file Codex CLI reads — Codex reads only config.toml. emitCodex now generates managed-block TOML; see D58.)