feat(llm): add Gonka protocol support

[golemcore1]

Summary

• Add Gonka apiType support to the Langchain4j LLM adapter by routing Gonka models through OpenAI chat completions with per-request ECDSA signing, requester-address derivation, timestamp headers, and transfer-agent endpoint resolution.
• Extend runtime LLM provider configuration, validation, model discovery auth handling, docs, and dashboard provider UI so Gonka profiles can be configured with sourceUrl, explicit url;transferAddress endpoints, and optional requester address.
• Add focused unit coverage for Gonka endpoint resolution, request signing, signed HTTP request headers, provider validation, discovery auth mode, and Langchain4j Gonka dispatch.

Verification performed:

• cd dashboard && npm run lint
• cd dashboard && npm run build
• ./mvnw -q -DskipTests compile -Dfrontend.skip=true -Dskip.npm=true -Dskip.installnodenpm=true
• Targeted Java tests via Surefire reports: Gonka adapter tests, Langchain4j adapter tests, provider discovery tests, runtime settings validator tests, provider model discovery tests, and architecture contract tests all reported 0 failures/errors.
• git diff --check

[sonarqubecloud]

Quality Gate failed

Failed conditions
75.5% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud