feat: add EvoLink provider config

[EvoLinkAI]

Summary

Adds EvoLink as a first-class OpenAI-compatible provider in OwnPilot's config-driven provider system.

• Adds packages/core/data/providers/evolink.json with https://direct.evolink.ai/v1 and a curated GPT-5 model set
• Registers evolink in the typed provider ID list
• Adds Settings UI metadata/category placement so EvoLink appears with other inference providers

Validation

• pnpm install --frozen-lockfile ✅
• node - <<'NODE' ... provider JSON sanity check ✅ (evolink provider config OK)
• pnpm --filter @ownpilot/core exec vitest run src/agent/providers/configs/index.test.ts ✅ 1 file, 126 tests passed, no type errors
• pnpm --filter @ownpilot/core typecheck ✅
• pnpm exec eslint packages/core/src/agent/providers/configs/index.ts packages/gateway/src/routes/providers.ts ✅
• pnpm exec prettier --check packages/core/data/providers/evolink.json packages/core/src/agent/providers/configs/index.ts packages/gateway/src/routes/providers.ts ✅ all matched files use Prettier style
• pnpm --filter @ownpilot/core build ✅
• pnpm --filter @ownpilot/gateway typecheck ✅
• pnpm --filter @ownpilot/gateway exec vitest run src/routes/providers.test.ts ✅ 1 file, 19 tests passed, no type errors
• Built export/provider factory smoke test via pnpm --filter @ownpilot/gateway exec node --input-type=module ... ✅ evolink openai-compatible 4 models default=gpt-5.2
• Real EvoLink endpoint call with workspace EVOLINK_API_KEY ✅ HTTP 200, response OK
• Real OwnPilot provider-path call through OpenAICompatibleProvider.fromProviderIdWithKey('evolink', ...) ✅ provider-path gpt-5.2-2025-12-11: OK

Notes

EvoLink's language API is OpenAI-compatible for chat completions, so this uses the existing generic OpenAICompatibleProvider rather than adding a new provider implementation.

[EvoLinkAI]

Validation evidence from local run:

• pnpm --filter @ownpilot/core exec vitest run src/agent/providers/configs/index.test.ts → 1 file passed, 126 tests passed, no type errors
• pnpm --filter @ownpilot/core typecheck → passed
• pnpm --filter @ownpilot/core build → passed
• pnpm --filter @ownpilot/gateway typecheck → passed after building @ownpilot/core
• pnpm --filter @ownpilot/gateway exec vitest run src/routes/providers.test.ts → 1 file passed, 19 tests passed, no type errors
• pnpm exec eslint packages/core/src/agent/providers/configs/index.ts packages/gateway/src/routes/providers.ts → passed
• pnpm exec prettier --check packages/core/data/providers/evolink.json packages/core/src/agent/providers/configs/index.ts packages/gateway/src/routes/providers.ts → all matched files use Prettier style
• Built export smoke test through @ownpilot/core/agent → evolink openai-compatible 4 models default=gpt-5.2
• Direct EvoLink API call to https://direct.evolink.ai/v1/chat/completions with gpt-5.2 → HTTP 200, response OK
• OwnPilot provider-path call via OpenAICompatibleProvider.fromProviderIdWithKey('evolink', ...) → provider-path gpt-5.2-2025-12-11: OK