fix: shift retrospective cron from 5AM to 4AM UTC to stay Sunday in CDT

feat: distinguish scheduled vs manual agent run triggers in UI

fix: replace @nestjs/schedule with node-cron to fix HF startup crash

fix: run Market Analyst at 8:30 AM EST (13:30 UTC) with force=true

feat: move agent scheduling from GitHub Actions cron to NestJS in-process

feat: add NestJS in-process scheduler to replace unreliable GitHub cron

Fix SPA refresh 500 and agent trigger error handling

Add GitHub Actions CI/CD, HF Space deployment, market hours guard, and static serving