feat(hyperopt): Complete DQN hyperopt analysis and PSO optimizer fix

- Fixed PSO budget calculation bug in ml/src/hyperopt/optimizer.rs
  - Root cause: Division by n_particles in sequential execution
  - Now correctly calculates max_iters = remaining_trials (no division)
  - Result: 50 trials complete instead of 23 (100% vs 46%)

- Added comprehensive DQN hyperopt results analysis
  - 39/50 trials analyzed across 2 RunPod deployments
  - Best hyperparameters identified: LR 4.89e-5 (ultra-low)
  - Created DQN_HYPEROPT_RESULTS_SUMMARY.md with expert validation

- GitLab CI/CD pipeline operational (48 lines fixed)
  - Fixed YAML syntax errors (unquoted colons)
  - All 7 jobs validated and working

- Warning cleanup complete (136 → 0 warnings)
  - Removed 143 lines dead code
  - Fixed visibility, unused imports, Debug traits

- Archived Wave D reports to docs/archive/
  - 8 early stopping reports moved
  - Root directory cleaned up

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

ml/src/backtesting/action_loader.rs

@@ -0,0 +1,194 @@
+// ml/src/backtesting/action_loader.rs
+// DQN action loader for CSV-based backtesting
+
+use chrono::{DateTime, Utc};
+use serde::Deserialize;
+use std::fs::File;
+use std::io::BufReader;
+use std::path::Path;
+
+/// DQN action record from CSV (13,552 actions, 10 columns)
+/// Format: timestamp,action,q_buy,q_sell,q_hold,open,high,low,close,volume
+#[derive(Debug, Clone, Deserialize)]
+pub struct DQNActionRecord {
+    /// ISO8601 timestamp (e.g., "2024-10-20T23:31:00.000000000Z")
+    pub timestamp: DateTime<Utc>,
+    
+    /// Action: 0=Buy, 1=Sell, 2=Hold
+    pub action: u8,
+    
+    /// Q-value for buy action
+    pub q_buy: f64,
+    
+    /// Q-value for sell action
+    pub q_sell: f64,
+    
+    /// Q-value for hold action
+    pub q_hold: f64,
+    
+    /// OHLCV data (for validation/debugging)
+    pub open: f64,
+    pub high: f64,
+    pub low: f64,
+    pub close: f64,
+    pub volume: u64,
+}
+
+/// Load DQN actions from CSV file
+///
+/// # Arguments
+/// * `csv_path` - Path to CSV file (e.g., "/tmp/dqn_actions_wave3.csv")
+///
+/// # Returns
+/// * `Ok(Vec<DQNActionRecord>)` - Parsed and validated actions
+/// * `Err(String)` - Validation errors (action bounds, Q-values, timestamps)
+///
+/// # Validations
+/// 1. Action bounds: 0 <= action <= 2
+/// 2. Finite Q-values: q_buy, q_sell, q_hold must be finite (no NaN/Inf)
+/// 3. Timestamp ordering: timestamps must be monotonically increasing
+///
+/// # Example
+/// ```ignore
+/// let actions = load_actions_from_csv("/tmp/dqn_actions_wave3.csv")?;
+/// assert_eq!(actions.len(), 13_552);
+/// ```
+pub fn load_actions_from_csv<P: AsRef<Path>>(csv_path: P) -> Result<Vec<DQNActionRecord>, String> {
+    let path = csv_path.as_ref();
+    
+    // Open CSV file
+    let file = File::open(path)
+        .map_err(|e| format!("Failed to open CSV file '{}': {}", path.display(), e))?;
+    
+    let reader = BufReader::new(file);
+    let mut csv_reader = csv::Reader::from_reader(reader);
+    
+    let mut actions = Vec::new();
+    let mut prev_timestamp: Option<DateTime<Utc>> = None;
+    let mut row_num = 1; // Start at 1 (header is row 0)
+    
+    for result in csv_reader.deserialize() {
+        row_num += 1;
+        
+        let record: DQNActionRecord = result
+            .map_err(|e| format!("CSV parsing error at row {}: {}", row_num, e))?;
+        
+        // Validation 1: Action bounds (0-2)
+        if record.action > 2 {
+            return Err(format!(
+                "Invalid action {} at row {} (timestamp {}): action must be 0 (Buy), 1 (Sell), or 2 (Hold)",
+                record.action,
+                row_num,
+                record.timestamp
+            ));
+        }
+        
+        // Validation 2: Finite Q-values
+        if !record.q_buy.is_finite() {
+            return Err(format!(
+                "Invalid q_buy {} at row {} (timestamp {}): Q-value must be finite",
+                record.q_buy,
+                row_num,
+                record.timestamp
+            ));
+        }
+        if !record.q_sell.is_finite() {
+            return Err(format!(
+                "Invalid q_sell {} at row {} (timestamp {}): Q-value must be finite",
+                record.q_sell,
+                row_num,
+                record.timestamp
+            ));
+        }
+        if !record.q_hold.is_finite() {
+            return Err(format!(
+                "Invalid q_hold {} at row {} (timestamp {}): Q-value must be finite",
+                record.q_hold,
+                row_num,
+                record.timestamp
+            ));
+        }
+        
+        // Validation 3: Timestamp ordering
+        if let Some(prev_ts) = prev_timestamp {
+            if record.timestamp < prev_ts {
+                return Err(format!(
+                    "Timestamp ordering violation at row {}: {} is before previous timestamp {}",
+                    row_num,
+                    record.timestamp,
+                    prev_ts
+                ));
+            }
+        }
+        prev_timestamp = Some(record.timestamp);
+        
+        actions.push(record);
+    }
+    
+    if actions.is_empty() {
+        return Err(format!("CSV file '{}' contains no data rows", path.display()));
+    }
+    
+    Ok(actions)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::TimeZone;
+    
+    #[test]
+    fn test_valid_action_record() {
+        // Test DQNActionRecord struct initialization
+        let record = DQNActionRecord {
+            timestamp: Utc.with_ymd_and_hms(2024, 10, 20, 23, 31, 0).unwrap(),
+            action: 2, // Hold
+            q_buy: -658.8440,
+            q_sell: 355.0268,
+            q_hold: 538.5875,
+            open: 5914.50,
+            high: 5914.75,
+            low: 5914.25,
+            close: 5914.25,
+            volume: 27,
+        };
+        
+        assert_eq!(record.action, 2);
+        assert!(record.q_buy.is_finite());
+        assert!(record.q_sell.is_finite());
+        assert!(record.q_hold.is_finite());
+    }
+    
+    #[test]
+    fn test_action_bounds_validation() {
+        // Test action bounds: 0 <= action <= 2
+        // Create a temporary CSV with invalid action
+        use std::io::Write;
+        let mut tmpfile = tempfile::NamedTempFile::new().unwrap();
+        writeln!(tmpfile, "timestamp,action,q_buy,q_sell,q_hold,open,high,low,close,volume").unwrap();
+        writeln!(tmpfile, "2024-10-20T23:31:00.000000000Z,3,-658.8440,355.0268,538.5875,5914.50,5914.75,5914.25,5914.25,27").unwrap();
+        tmpfile.flush().unwrap();
+        
+        let result = load_actions_from_csv(tmpfile.path());
+        assert!(result.is_err());
+        let err = result.unwrap_err();
+        assert!(err.contains("Invalid action 3"));
+        assert!(err.contains("action must be 0 (Buy), 1 (Sell), or 2 (Hold)"));
+    }
+    
+    #[test]
+    fn test_finite_qvalue_validation() {
+        // Test finite Q-value validation (NaN/Inf detection)
+        use std::io::Write;
+        let mut tmpfile = tempfile::NamedTempFile::new().unwrap();
+        writeln!(tmpfile, "timestamp,action,q_buy,q_sell,q_hold,open,high,low,close,volume").unwrap();
+        writeln!(tmpfile, "2024-10-20T23:31:00.000000000Z,2,NaN,355.0268,538.5875,5914.50,5914.75,5914.25,5914.25,27").unwrap();
+        tmpfile.flush().unwrap();
+        
+        let result = load_actions_from_csv(tmpfile.path());
+        assert!(result.is_err());
+        let err = result.unwrap_err();
+        assert!(err.contains("Invalid q_buy"));
+        assert!(err.contains("Q-value must be finite"));
+    }
+}