feat: Complete Ask Ash AI Credits implementation on high-performance branch (Tasks 1-10)
- Task 1: Admin endpoints for wallet management
- Task 2: AI Credits admin UI (pricing.tsx, credit.tsx)
- Task 3: Ollama security (NetworkPolicy, prompt validation, audit)
- Task 4: LiteLLM integration (litellm.rs, migrated AI feature handlers)
- Task 5: Refund architecture (ai_refunds table, endpoints)
- Task 6: Coupons, promotions, referrals (order creation with coupon)
- Task 7: Subscription lifecycle (plan upgrades/downgrades, cron jobs)
- Task 8: Credit expiration enforcement (daily cron task)
- Task 9: Token cost engine (ai_model_cost_config, margin view)
- Task 10: Observability (metrics tables, aggregation function)
Cherry-picked from main branch commit 3c0f45f
0dd5045676