Implement AionLabs AI adapter

[op-simoneromeo]

Summary

• replace the AionLabs AI stub with an OpenAI-compatible chat-completions adapter
• add default AionLabs API base/model metadata and token-safe dry-run behavior
• add mocked request/response/error tests for the adapter

Validation

• corepack pnpm@9.12.0 exec vitest run packages/ai/aionlabs/src/index.test.ts
• corepack pnpm@9.12.0 --filter @profullstack/sh1pt-ai-aionlabs typecheck
• corepack pnpm@9.12.0 --filter @profullstack/sh1pt-ai-aionlabs build
• git diff --check
• secret-pattern scan over changed AionLabs files

Refs #6