Handle backend errors gracefully, fix MSD volume/demand field

- Generation loop catches RuntimeError/OSError from backend (timeout,
  connection refused) and treats as iteration error instead of crashing
- MSD compute_alpha_star reads 'volume' field (ngraph's key) with
  'demand' as fallback for backward compatibility
- MSD accepts 'msd' as step name in addition to 'msd_baseline'

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Andrey Golovanov

metrics/msd.py

@@ -22,12 +22,17 @@ def to_jsonable(self) -> dict:
 
 
 def compute_alpha_star(results: dict) -> AlphaResult:
-    msd = results.get("steps", {}).get("msd_baseline", {}).get("data", {}) or {}
+    steps = results.get("steps", {})
+    # Accept common MSD step names
+    msd_step = steps.get("msd_baseline") or steps.get("msd") or {}
+    msd = msd_step.get("data", {}) or {}
     alpha = msd.get("alpha_star", None)
     base_total = np.nan
     try:
         base_demands = msd.get("base_demands", [])
-        base_total = float(sum([float(x.get("demand", 0.0)) for x in base_demands]))
+        base_total = float(
+            sum(float(x.get("volume", x.get("demand", 0.0))) for x in base_demands)
+        )
     except Exception:
         base_total = np.nan
 

netlab/autoresearch/generation_loop.py

@@ -339,7 +339,16 @@ def run_generation_loop(
                     validation_errors=validation_errors,
                 )
 
-            response = backend.generate(prompt, system=_get_generation_system_prompt())
+            try:
+                response = backend.generate(
+                    prompt, system=_get_generation_system_prompt()
+                )
+            except (RuntimeError, OSError) as exc:
+                last_inspect = InspectResult(
+                    success=False,
+                    errors=[f"LLM backend error: {exc}"],
+                )
+                continue
 
             # Extract YAML from response
             yaml_text = _extract_yaml(response)

tests/autoresearch/test_infrastructure.py

@@ -105,14 +105,13 @@ def test_metadata_lacks_baseline_flag(self, square_mesh_results: dict) -> None:
         assert "baseline" not in tm_meta or tm_meta.get("baseline") is not True
 
     def test_compute_alpha_star_works(self, square_mesh_results: dict) -> None:
-        """compute_alpha_star extracts alpha_star but gets base_total_demand=0 due to key mismatch."""
+        """compute_alpha_star extracts alpha_star and base_total_demand."""
         from metrics.msd import compute_alpha_star
 
         alpha = compute_alpha_star(square_mesh_results)
         assert alpha.alpha_star == 1.0
-        # base_total_demand is 0.0 because compute_alpha_star looks for 'demand' key
-        # but current ngraph uses 'volume'
-        assert alpha.base_total_demand == 0.0
+        # base_total_demand reads 'volume' field (ngraph's key) with 'demand' as fallback
+        assert alpha.base_total_demand == 12.0
 
 
 class TestSampleTemplate: