feat: agent 0.12.7 (model dropdown in key wizard)

[protosphinx]

Summary

• Extended the local key wizard at 127.0.0.1:4242 with a provider+model picker so the active model is one click away (no more hand-editing config.json or typing dotted OpenRouter slugs from memory).
• For OpenRouter, the model <select> is hydrated live from openrouter.ai/api/v1/models (proxied via a new /openrouter-models endpoint, cached 1h, shared across tabs). Options are sorted cheapest first and labeled with in $X/M · out $Y/M · N k ctx so Kimi K2, MiniMax, DeepSeek, Llama and Qwen are easy to spot when Opus 4.7 starts hurting.
• Save now writes shared-keys.json (keys) and the active profile's config.json (provider, model) in one round-trip. Flow is paste-key → pick-model → Save → say go.
• Selecting an OpenRouter-style slug while the provider is anthropic (or vice versa) gets repaired at save time via normalizeModelForProvider, so on-disk state is always clean.
• Expanded MODEL_SUGGESTIONS.openrouter from 4 to 14 entries so the fallback list (when live fetch fails) is still useful.

Test plan

• pnpm typecheck clean
• pnpm build clean
• Smoke: boot server, GET / renders provider + model selects, fallback map present
• Smoke: GET /openrouter-models returns 345 models (200 OK, cached)
• Smoke: POST /save with { provider: 'openrouter', model: 'moonshotai/kimi-k2' } flips per-profile config.json from anthropic / claude-opus-4-7 → openrouter / moonshotai/kimi-k2
• Manual: type /keys in chat, pick a non-Opus model, send a message, verify next turn uses the new model