feat: add --config CLI flag for interactive provider/model setup

[Hridoy Ahmed (hrid0yyy)]

Summary

Add --config CLI flag that opens an interactive wizard to change provider, model, and API key settings without running the main wiki session.

Changes

• src/commands.ts — Added config command kind; parses --config flag; updated help text
• src/credentials.tsx — Added forceConfig prop to InitSetup so it always starts from provider selection step
• src/cli.tsx — Added ConfigView component that runs the wizard with forceConfig, shows a summary on completion, then auto-exits; wired up entry point to load env for config runs; fixed command.dryRun type guard

What --config does

Running openwiki --config launches an interactive wizard that walks you through configuring OpenWiki:

1. Provider — Select from openrouter, baseten, fireworks, openai, or anthropic
2. API key — Enter the API key for the chosen provider
3. Model — Pick from the provider's preset models or type a custom model ID
4. LangSmith — Optionally set up LangSmith tracing

Each step is skipped if already configured. Changes are saved to ~/.openwiki/.env and persist across sessions.

Usage

openwiki --config                           # configure from scratch
openwiki --config --modelId claude-sonnet-5  # pre-select a model

[PRATHAM KUMAR (rajpratham1)]

This is a useful UX improvement with a relatively small, well-contained implementation.

Pros
✅ Adds a dedicated --config command for updating provider, model, and API keys without triggering a normal run.
✅ Reuses the existing InitSetup flow instead of duplicating logic.
✅ Keeps backward compatibility (--init, --update, normal runs unchanged).
✅ Updates CLI help and examples.
✅ forceConfig cleanly starts at the provider selection screen.
Things to verify before merge
Ensure --config cannot be combined with incompatible flags like --init, --update, or a prompt. If it can, the parser should reject conflicting combinations.
Confirm the new summary screen exits correctly on all terminals (auto-exit after 3s and key press both work).
Add CLI tests for:
openwiki --config
openwiki --config --modelId ...
invalid combinations (--config --update, --config "prompt" if unsupported).

[Hridoy Ahmed (hrid0yyy)]

I've addressed the review feedback and pushed the requested changes. I'd appreciate another review when you have time. Thank you!

[Colin Francis (colifran)]

Thanks for the PR! This is going to be superseded by #374 which makes init idempotent so re-running it allows you to reconfigure things.