feat(example): add L2 classifications for 823/988 WoN entities (S3.4)

Batch classification via OpenRouter (claude-sonnet-4). 165 entities
remain unclassified due to credit exhaustion; incremental skip means
a follow-up run will complete them automatically.

Type × VSM matrix (823 entities):
                  S1   S2   S3  S3*   S4   S5
  Element         86   75   58   21   43   32  (315 total, 38%)
  Process         39   42   37   17   67   24  (226 total, 28%)
  Institution      4   12   30   24    .   52  (122 total, 15%)
  Principle        3    7   15    2   43   32  (102 total, 12%)
  Relation         2   14    5    5   22   10   (58 total,  7%)
  Matrix fill: 29/30 cells (Institution/S4 empty — expected)

Metrics updated: type_entropy=2.0936, vsm_type_matrix_cells=29

Also:
- BatchEvaluator gains delay_seconds param for rate-limited providers
- classify CLI gains --rpm option (--rpm 10 for Gemini free tier)
- history.write_metrics_file now handles non-float metric values
  (type_distribution is a dict, was crashing round())
- run_entity_classification forwards delay_seconds to BatchEvaluator
- classify-links and graph commands added by user (entities --by-type,
  graph --format mermaid/dot, classify-links for Relation enrichment)

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

examples/infospace-with-history/output/classifications/barbarous_nations_barrier.md

@@ -0,0 +1,31 @@
+---
+entity_slug: barbarous_nations_barrier
+entity_type: Element
+vsm_system: S4
+type_rationale: The barbarous nations barrier is a persistent obstacle or impediment
+  that exists independently as a structural feature of the trading environment, rather
+  than being a process, relationship, or abstract principle.
+vsm_rationale: This barrier functions as an environmental constraint that must be
+  scanned and analyzed when assessing trade opportunities and market development possibilities,
+  which is the core intelligence function of understanding external conditions affecting
+  the economic system.
+classified_at: '2026-02-23T10:47:51.797735'
+---
+
+# Classification: Barbarous Nations Barrier
+
+## Entity Type
+
+Element
+
+## VSM System
+
+S4
+
+## Type Rationale
+
+The barbarous nations barrier is a persistent obstacle or impediment that exists independently as a structural feature of the trading environment, rather than being a process, relationship, or abstract principle.
+
+## VSM Rationale
+
+This barrier functions as an environmental constraint that must be scanned and analyzed when assessing trade opportunities and market development possibilities, which is the core intelligence function of understanding external conditions affecting the economic system.