feat(model): bring your own key through ai-kit — every vendor, the key's own models, no paid check

[catomean]

Heidi's part of the fleet-wide "make it easy to power with the smartest model you have" (George, relayed by the Loki session; reference bitbaum/loki#921).

Before (measured)

• Heidi kept its own 5-vendor BYOK_PROVIDERS: no Anthropic, no Gemini.
• The model was a free-text field with a guessed default.
• /api/model/check spent a real completion to test a key.

Now

• Vendors from @bitbaum/ai-kit BYOK_VENDORS (bumped to ^1.17.0), 10 in total:
  • OpenRouter, OpenAI, Anthropic, Google Gemini, Groq, Mistral, DeepSeek, xAI, Together, Cerebras.
  • byokChain delegates to ai-kit's. Heidi pins dailyTokens: 0 on the reader's link: ai-kit marks it unmetered, and Heidi's free chain shares provider ids, so an unmetered entry could otherwise read as capacity in our pool.
• /api/model/check → probeByokKey
  • No tokens spent.
  • Returns the key's own models with suggested.
  • On failure: the vendor's words, redacted again here.
  • "Unreachable" is kept apart from "wrong key".
• The sheet
  • Choose vendor → paste key → auto-check after 600 ms.
  • A select of the key's models, strongest preselected and marked ("— stärkstes").
  • Free text only when the vendor lists none.
  • Failure shows our localised sentence, then "Der Anbieter meldet: …".
  • The key stays in this browser only; unchanged privacy choice.
• No per-vendor "text only" guess. ai-kit routes images on observed capability.
• New strings in all 7 languages; the unused "can read pictures / text only" labels were removed.

Also fixed: "No streaks" was still claimed in 7 languages (landing pillar, method line, a sourced method claim) after streaks shipped. Reworded to what's true: no points, no invented numbers, and a streak without reproach.

Checked

• pnpm run verify green (913 pass).
• New route tests (probe mocked): bad input refused before any call; models and suggestion passed through; key redacted; unreachable ≠ wrong key.
  • Mutation-checked: removing the redaction fails the redaction test, and collapsing "unreachable" fails the unreachable test.
• Browser at 390px (check endpoint intercepted):
  • 10 vendors offered; one check request 0.6 s after pasting;
  • the model select shows 3 models with claude-opus-5 — stärkstes preselected;
  • "Dieses Modell verwenden" stores {provider, key, model} in localStorage;
  • the failure shows the vendor's credit message;
  • no horizontal scroll.

🤖 Generated with Claude Code