feat: Add historical rollout viewing with S3 storage support

[soovittt]

Changes

• ✅ Add ability to view previous rollouts from history
• ✅ Implement S3 storage for full rollout data
• ✅ Add in-memory cache for recent rollouts (last 10)
• ✅ Add backend endpoint to load rollouts from S3
• ✅ Improve RL Analysis tab with better data visualization
• ✅ Fix reward calculation in backend simulator (reach_goal, step, hit_trap, collect_key conditions)
• ✅ Add validation for action space and dynamics
• ✅ Clean up unnecessary files (dev.txt, prod.txt, check_aws_account.py, s3_bucket_setup.py)
• ✅ Update .gitignore to exclude token files

Technical Details

• Historical rollouts are saved with summary data to Convex (to avoid 1MB limit)

• Full rollout data is stored in S3 with compression

• When clicking a history item, the system:

  1. Checks in-memory cache first (fastest)
  2. Falls back to loading from S3 if available
  3. Shows helpful error if data is unavailable

• All tabs (Reward Inspector, Event Log, RL Analysis) automatically use the selected rollout

• New rollouts automatically clear history selection and switch to new data