chore(ai): rename the openai-compatible provider options key

[mrsibe]

What

One constant: PROVIDER_OPTIONS_KEY 'openai-compatible' → 'openaiCompatible'.

AI SDK 7 deprecates the kebab-case providerOptions key for @ai-sdk/openai-compatible. The provider still reads it, but it logs a deprecation warning on every call and files providerMetadata under the old key.

The constant already served as both the provider name and the options key, and the provider derives the metadata key from whichever key the caller sends, so one change keeps all three consistent:

export const PROVIDER_OPTIONS_KEY = 'openaiCompatible'

Verification: real provider, captured fetch, three cases

Not a constant test — the actual request body and the actual warning stream:

key='openai-compatible'  reasoning_effort=low  + DeprecationWarning
key='openaiCompatible'   reasoning_effort=low  (no warning)
key=<none>               no reasoning field

Behaviour is unchanged and the warning is gone. The reasoning configuration still reaches the request as reasoning_effort.

The providerMetadata consequence, covered

Because the provider namespaces providerMetadata by the options key, this moves providerMetadata['openai-compatible'] → providerMetadata['openaiCompatible']. Two things make that safe, and the second is a test rather than a promise:

1. A repository-wide search for providerMetadata in src/ returns nothing — no UI, logging or debug consumer depends on either key.

2. test/connectionCapabilities.test.ts now drives the real provider through a mocked SSE response and asserts:

   assert.deepEqual(Object.keys(await result.providerMetadata), [PROVIDER_OPTIONS_KEY])

   plus that the constant is literally openaiCompatible. Reverting to the deprecated key now fails a test instead of only emitting a warning.

Scope

Only src/main/models/protocols/openaiCompletions.ts and its test. name, baseURL and apiKey are untouched; the provider id and request shape do not change.

Verified

• npm run typecheck — clean
• npm test — 472/472 pass (471 + the metadata-shape test)
• npm run build — OK

No dependency, native addon, packaging or schema change, so no packaged smoke — agreed with the reviewer, and consistent with CONTRIBUTING's rule (packaged checks are for Electron main/preload, dependencies, native addons, packaging, DB init or build config).

Follow-up

The streamObject deprecation migration is next, separately, and not stacked on this: characterization tests for QuizService / AnkiCardService / MindMapService first (partial-object order and visibility, progress callback count and timing, the final object, provider-error propagation, abort behaviour), then the migration.