Bound the AI copywriting LLM call and route service logs through pino

Commit notes

The pack copywriting endpoint called generateText with no timeout and default retries, unlike the interactive search planner's 2.5s abort budget; a slow/hung OpenAI response could hold the request open for minutes. Also switch ai-copywriting.ts and similarity-search.ts from console.error/warn to the repo-standard pino logger so these failures get structured logging in production.

Co-Authored-By: Claude Fable 5 <[email redacted]> Claude-Session: [private session redacted]