fix: Add chi_g peak fallback for Re_crit + smoke test infrastructure

- thermal_pump.py: If Cv peak hasn't fired by chi_g peak, derive Re_crit
  from chi_g peak conditions (also a valid phase transition marker)
- sprint_c_tower_validation.py: Add --smoke_test, --verbose, --early_stop_on_grok
- Smoke test uses --quick mode (p=17) for faster verification
- Verbose mode shows Cv, Re_SGC, Re_crit in training log

Smoke test verified:
  Cv peak detected: True
  T_peak = 1.0000
  Re_crit = 0.0100 (SELF-DERIVED)

[GO] Thermodynamic control loop verified. Ready for full run.

Author: JasonShroyer

perihelion/core/thermal_pump.py

@@ -201,6 +201,11 @@ def detect_chi_g_peak(self) -> bool:
         ZERO-PARAMETER: No threshold comparison.
         Peak is when d(chi_g)/dt changes from positive to negative.
         This is a detectable event, not a threshold.
+        
+        FALLBACK: If Cv peak hasn't been detected by the time chi_g peaks,
+        use the chi_g peak conditions to derive Re_crit. This ensures the
+        Fermi quench has a valid critical Reynolds number even when
+        energy variance is too low for Cv peak detection.
         """
         if len(self.chi_g_history) < 10:
             return False
@@ -220,6 +225,13 @@ def detect_chi_g_peak(self) -> bool:
                 self.chi_g_peak_detected = True
                 self.chi_g_peak_epoch = self.epoch
                 self.chi_g_peak_value = max(recent)
+                
+                # FALLBACK: If Cv peak hasn't fired, derive Re_crit from chi_g peak
+                # chi_g peak is also a valid phase transition marker
+                if not self.Cv_peak_detected and self.grad_epsilon_norm > 1e-10:
+                    self.Re_crit = (self.kappa * self.temperature * self.lambda_pump) / self.grad_epsilon_norm
+                    print(f"[ThermalPump] chi_g PEAK -> Re_crit = {self.Re_crit:.4f} (FALLBACK)")
+                
                 return True
 
         return False

perihelion/experiments/sprint_c_tower_validation.py

@@ -648,10 +648,23 @@ def train_task(self, task) -> TaskResult:
                 if step % self.log_interval == 0:
                     train_acc, test_acc = self.compute_accuracy(task_name)
                     sigma_q = self.controller.thermal.get_fermi_quench_factor()
-                    print(f"Step {step:5d} | Train: {train_acc:.3f} | Test: {test_acc:.3f} | "
-                          f"eps: {metrics.epsilon:.4f} | R: {metrics.ridge_ratio:.2f} | "
-                          f"T: {self.controller.thermal.temperature:.2f} | "
-                          f"sigma_q: {sigma_q:.3f}")
+                    thermal = self.controller.thermal
+                    
+                    # Basic metrics
+                    log_line = (f"Step {step:5d} | Train: {train_acc:.3f} | Test: {test_acc:.3f} | "
+                               f"eps: {metrics.epsilon:.4f} | R: {metrics.ridge_ratio:.2f} | "
+                               f"T: {thermal.temperature:.2f} | sigma_q: {sigma_q:.3f}")
+                    
+                    # Verbose: add Cv and Re_SGC tracking
+                    if getattr(self, 'verbose', False):
+                        Cv = 0.0
+                        if len(thermal.Cv_history) > 0:
+                            Cv = thermal.Cv_history[-1][1]
+                        log_line += f" | Cv: {Cv:.3f} | Re: {thermal.Re_SGC:.3f}"
+                        if thermal.Cv_peak_detected:
+                            log_line += f" | Re_crit: {thermal.Re_crit:.3f}"
+                    
+                    print(log_line)
 
                 # Phase 3: Preservation monitoring
                 if step % self.preservation_check_interval == 0 and self.tower_result.tasks:
@@ -773,12 +786,28 @@ def main():
     parser.add_argument('--output', type=str, default='sprint_c_tower_result.json')
     parser.add_argument('--quick', action='store_true',
                         help='Quick test with reduced parameters')
+    parser.add_argument('--verbose', action='store_true',
+                        help='Verbose logging including Cv tracking')
+    parser.add_argument('--smoke_test', action='store_true',
+                        help='Run 500-step smoke test to verify Cv peak detection')
+    parser.add_argument('--early_stop_on_grok', action='store_true',
+                        help='Stop task immediately after grokking (for smoke test)')
 
     args = parser.parse_args()
 
+    # Smoke test mode
+    if args.smoke_test:
+        args.max_steps = 500
+        args.verbose = True
+        args.early_stop_on_grok = True
+        args.quick = True  # Use smaller prime for smoke test
+        print("\n" + "="*60)
+        print("SMOKE TEST MODE: 500 steps, watching for Cv peak")
+        print("="*60)
+    
     if args.quick:
-        args.max_steps = 2000
-        prime = 17
+        args.max_steps = min(args.max_steps, 2000)
+        prime = 17  # Smaller prime for quick/smoke tests
     else:
         prime = 97
 
@@ -796,13 +825,33 @@ def main():
         hidden_dim=args.hidden_dim,
         device=args.device,
         max_steps_per_task=args.max_steps,
-        log_interval=100,
+        log_interval=50 if args.verbose else 100,
         preservation_check_interval=500
     )
 
+    # Pass verbosity setting
+    conductor.verbose = getattr(args, 'verbose', False)
+    conductor.early_stop_on_grok = getattr(args, 'early_stop_on_grok', False)
+    conductor.smoke_test = getattr(args, 'smoke_test', False)
+    
     result = conductor.run()
     conductor.save_results(args.output)
 
+    # Smoke test summary
+    if args.smoke_test:
+        print("\n" + "="*60)
+        print("SMOKE TEST SUMMARY")
+        print("="*60)
+        cv_detected = conductor.controller.thermal.Cv_peak_detected
+        print(f"Cv peak detected: {cv_detected}")
+        if cv_detected:
+            print(f"  T_peak = {conductor.controller.thermal.Cv_peak_temperature:.4f}")
+            print(f"  Re_crit = {conductor.controller.thermal.Re_crit:.4f} (SELF-DERIVED)")
+            print("\n[GO] Thermodynamic control loop verified. Ready for full run.")
+        else:
+            print("\n[WAIT] Cv peak not detected in 500 steps.")
+            print("  Check energy tracking in thermal_pump.update_energy()")
+    
     return result