feat(infospace): add eval-summary command and improve evaluate pipeline (S3.3)

- Fix evaluate dimensions to match template file:
  definition_precision, source_grounding, domain_placement,
  vsm_relevance, explanatory_value (was domain_relevance,
  discipline_alignment, conceptual_clarity)
- Add VSM background context to evaluation prompt so LLM can
  score vsm_relevance without macro injection
- Fix model_name bug: was sending literal "default" to API (HTTP 400)
- Refactor run_entity_evaluation to write files incrementally via
  callback rather than all at once after the batch — long runs are
  now resumable if interrupted
- Add incremental skip in CLI: entities with existing eval files
  are skipped automatically on re-run (acts as resume)
- Add eval-summary command: reads all eval files, shows per-dimension
  means, optionally writes per_entity_mean to metrics.yaml
- Fix record_check_results to merge rather than overwrite metrics.yaml
  so per_entity_mean survives subsequent check runs
- Add per_entity_mean viability threshold (min: 3.5) to infospace.yaml

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

markitect/infospace/history.py

@@ -131,8 +131,11 @@ def record_check_results(
     metrics_dir = root / config.metrics_dir
     metrics = check_report.metrics()
 
-    # Save latest metrics
-    write_metrics_file(metrics, metrics_dir / "metrics.yaml")
+    # Save latest metrics — merge with existing so other metric sources
+    # (e.g. per-entity evaluation summary) are preserved across check runs.
+    existing = read_metrics_file(metrics_dir / "metrics.yaml")
+    merged = {**existing, **metrics}  # check results overwrite on key conflict
+    write_metrics_file(merged, metrics_dir / "metrics.yaml")
 
     # Create and append snapshot
     snapshot = snapshot_from_checks(