refactor(joinir): Phase 71-Pre - OwnershipPlanValidator Box (dev-only)

pattern3_with_if_phi.rs の check_ownership_plan_consistency() を独立した
OwnershipPlanValidator Box に抽出。P2/P4 での再利用を可能にする。

Key changes:
- plan_validator.rs: 新規作成 (~190行)
  - validate_relay_support(): Multi-hop relay Fail-Fast (Phase 70-A タグ)
  - validate_carrier_consistency(): Carrier set 整合性チェック (warn-only)
  - validate_condition_captures(): Condition captures チェック (warn-only)
  - validate_all(): All-in-one 検証

- pattern3_with_if_phi.rs: Validator box への委譲
  - check_ownership_plan_consistency() → OwnershipPlanValidator::validate_all()

Unit tests: 3 PASS
- test_validate_relay_support_single_hop_ok
- test_validate_relay_support_multihop_rejected
- test_validate_all_with_consistent_data

Tests: normalized_dev 50/50 PASS, lib 950/950 PASS

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/mir/builder/control_flow/joinir/patterns/pattern3_with_if_phi.rs

@@ -311,63 +311,13 @@ impl MirBuilder {
 /// 3. **Condition captures consistency**: plan captures vs condition bindings (warn-only)
 ///
 /// Phase 70-A: Standardized error tag for runtime unsupported patterns.
+/// Phase 71-Pre: Delegated to OwnershipPlanValidator box.
 #[cfg(feature = "normalized_dev")]
 fn check_ownership_plan_consistency(
     plan: &crate::mir::join_ir::ownership::OwnershipPlan,
     carrier_info: &crate::mir::join_ir::lowering::carrier_info::CarrierInfo,
     condition_bindings: &std::collections::BTreeSet<String>,
 ) -> Result<(), String> {
-    use std::collections::BTreeSet;
-
-    // Check 1: Multi-hop relay is rejected (Fail-Fast)
-    // Tag: [ownership/relay:runtime_unsupported] - standardized for Phase 70-A
-    for relay in &plan.relay_writes {
-        if relay.relay_path.len() > 1 {
-            return Err(format!(
-                "[ownership/relay:runtime_unsupported] Multihop relay not executable yet: var='{}', owner={:?}, relay_path={:?}",
-                relay.name, relay.owner_scope, relay.relay_path
-            ));
-        }
-    }
-
-    // Check 2: Carrier set consistency (warn-only, order SSOT deferred)
-    let plan_carriers: BTreeSet<String> = plan
-        .owned_vars
-        .iter()
-        .filter(|v| v.is_written)
-        .map(|v| v.name.clone())
-        .collect();
-
-    let existing_carriers: BTreeSet<String> = carrier_info
-        .carriers
-        .iter()
-        .map(|c| c.name.clone())
-        .collect();
-
-    if plan_carriers != existing_carriers {
-        eprintln!("[phase64/ownership] Carrier set mismatch (warn-only, order SSOT deferred):");
-        eprintln!("  OwnershipPlan carriers: {:?}", plan_carriers);
-        eprintln!("  Existing carriers: {:?}", existing_carriers);
-        // Don't fail - just warn (order SSOT not yet implemented)
-    }
-
-    // Check 3: Condition captures consistency (warn-only)
-    let plan_cond_captures: BTreeSet<String> = plan
-        .condition_captures
-        .iter()
-        .map(|c| c.name.clone())
-        .collect();
-
-    if !plan_cond_captures.is_subset(condition_bindings) {
-        let extra: Vec<_> = plan_cond_captures
-            .difference(condition_bindings)
-            .collect();
-        eprintln!(
-            "[phase64/ownership] Extra condition captures in plan (warn-only): {:?}",
-            extra
-        );
-        // Warn only - this might be expected in some cases
-    }
-
-    Ok(())
+    use crate::mir::join_ir::ownership::OwnershipPlanValidator;
+    OwnershipPlanValidator::validate_all(plan, carrier_info, condition_bindings)
 }