feat: Wave 2 - Update MEDIUM RISK files (225→54 features)

WAVE 22: All examples, benchmarks, and data loaders updated

Files Modified (41 files):
- DQN examples: 7 files (train_dqn, evaluate_dqn, validate_dqn, etc.)
- PPO examples: 6 files (train_ppo, continuous_ppo, benchmark_ppo, etc.)
- TFT examples: 9 files (train_tft, validate_tft, benchmark_tft, etc.)
- MAMBA-2 examples: 3 files (train_mamba2, verify_dimensions, etc.)
- Benchmarks: 5 files (cuda_speedup, weight_caching, future_decoder, etc.)
- Data loaders: 7 files (parquet_utils, dbn_sequence_loader, tlob_loader, etc.)
- Integration: 4 files (load_parquet_data, streaming loaders, etc.)

Key Changes:
- state_dim: 225 → 54 (DQN, PPO)
- input_dim: 225 → 54 (TFT)
- d_model: 225 → 54 (MAMBA-2)
- Memory: 1.8KB → 0.43KB per vector (76% reduction)
- All tensor shapes updated: (batch, 225) → (batch, 54)

Agents Deployed: 5 parallel agents
Validation: cargo check PASSING

Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

ml/examples/test_future_decoder.rs

@@ -7,7 +7,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // Create TFT config
     let config = TFTConfig {
-        input_dim: 225,
+        input_dim: 54,
         hidden_dim: 256,
         num_heads: 8,
         num_known_features: 10,