feat(sync): add kilo provider

[levdad]

Implements sync support for Kilo Gateway in packages/core/src/sync/providers/kilo.ts.

• Fetches models from https://api.kilo.ai/api/gateway/models
• Supports optional KILO_API_KEY authentication
• Handles deprecated/unavailable models gracefully
• Derives reasoning_options from opencode.variants
• Preserves existing hand-authored fields (status, interleaved, knowledge, limit.input, cost.tiers)

[levdad]

this will fix #2036

[rekram1-node]

is the key needed or is it optional?

[levdad]

is the key needed or is it optional?

The key is needed to use the kilo provider, but it is not needed to get the list of available models.

[github-actions]

Action items

• [medium] [violation] packages/core/src/sync/providers/kilo.ts (diff lines 91-92, 100-102, 386-517) - Check: Provider modules must not contain TOML scanning or generic comparison logic. Why: kilo.ts duplicates ~130 lines of helpers from openrouter.ts (modelMetadataExists, baseModelOmit, baseModelOverrides, inheritedOverride, stripUndefined, sameInheritedValue, stableInheritedValue, isPlainObject, modelMetadata, canonicalCandidates) plus the module-level MODELS_DIR, modelMetadataByID, modelMetadataFilesByProvider, and the readFileSync/readdirSync/path imports. None of these are reachable from kilo.translateModel/buildKiloModel — the module already imports factorBaseModel and resolveCanonicalBaseModel from openrouter.ts, which use OpenRouter's own internal copies of these helpers. This dead block both violates sync.md's "Do not put TOML scanning, writing, deletion, reporting, or generic comparison logic in provider modules" and ships unreachable filesystem/TOML-reading code that can mislead future maintainers. Action: Delete the unused helper cluster (modelMetadataExists through canonicalCandidates), the module-level MODELS_DIR/modelMetadataByID/modelMetadataFilesByProvider maps, and the now-unused readFileSync/readdirSync/path imports; rely on the imported factorBaseModel/resolveCanonicalBaseModel for base-model factoring.