- Add cache::ai module with Redis rate limiting for AI generations
- Add functions: check_ai_rate_limit, get_ai_usage, cache_ai_response,
get_cached_ai_response, invalidate_ai_cache, reset_daily_usage
- Update check_and_increment_usage to use Redis fast-path before DB
- Redis key pattern: ai:rate:{user_id} for 24hr sliding window counter
- Fix gateway: add /api/ai route to users_url
- Add AI job field generation endpoints (generate-job-field, generate-cover-letter, tailor-resume, auto-apply)
- Add AI usage tracking and rate limiting
- Add professional auto-respond-to-lead endpoint (30 tracecoins)
- Add DB migrations for AI usage tracking tables
- Update leads service with AI auto-respond functionality
- Add /api/ai/chat/message: LLM-powered chat with intent classification
- Add /api/ai/tickets/create and /api/ai/tickets/🆔 AI ticket management
- Add /api/ai/forms/extract: LLM-powered form field extraction
- Add /api/support/tickets/ai/create: unauthenticated ticket creation for AI service
- Add reqwest to workspace dependencies
