feat(iso): HasVisualization + viz_manifest wiring for Requirement/Decision/Cost

crates/arc-kit-au/src/node.rs

@@ -124,7 +124,7 @@ pub fn content_hash(parts: &[&str]) -> String {
 }
 
 /// Source document evidence.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct SourceDoc {
     /// Original filename (must follow VENDOR--ACCOUNT--YYYY-MM--DOCTYPE.ext)
     pub filename: String,
@@ -151,7 +151,7 @@ impl SourceDoc {
 }
 
 /// Extracted row from document parsing.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct ExtractedRow {
     pub account_id: String,
     pub date: String,
@@ -176,7 +176,7 @@ impl ExtractedRow {
 }
 
 /// Deterministic transaction record.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct Transaction {
     /// Blake3 hash of account/date/amount/description
     pub tx_id: String,
@@ -194,7 +194,7 @@ impl Transaction {
 }
 
 /// Classification applied to transaction.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct Classification {
     pub tx_id: String,
     pub category: String,
@@ -221,7 +221,7 @@ impl Classification {
 }
 
 /// Model-generated classification proposal.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct ModelProposal {
     pub tx_id: String,
     pub model_name: String,
@@ -247,7 +247,7 @@ impl ModelProposal {
 }
 
 /// Operator approval/rejection of model proposal.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct OperatorApproval {
     pub tx_id: String,
     pub operator_id: String,
@@ -275,7 +275,7 @@ impl OperatorApproval {
 /// Distinct from Classification — validation artifacts represent rule/constraint
 /// failures, not categorization decisions. PRD-4 Phase 2 requires
 /// classification_artifact → validation_artifact as a separate chain step.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct ValidationIssue {
     pub tx_id: String,
     pub rule: String,
@@ -301,7 +301,7 @@ impl ValidationIssue {
 }
 
 /// Final workbook row in CPA export.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, SysmlBlock)]
 pub struct WorkbookRow {
     pub tx_id: String,
     pub sheet_name: String,

crates/ledger-core/src/iso.rs

@@ -137,6 +137,12 @@ pub enum SemanticType {
     Issue,
     Proof,
     Attestation,
+    /// SysML-v2 systems-modeling requirement record — see `ZLayer::SystemsModel`.
+    Requirement,
+    /// SysML-v2 systems-modeling decision record — see `ZLayer::SystemsModel`.
+    Decision,
+    /// SysML-v2 systems-modeling cost record — see `ZLayer::SystemsModel`.
+    Cost,
     Unknown,
 }
 
@@ -155,6 +161,9 @@ impl SemanticType {
             SemanticType::Issue => "issue",
             SemanticType::Proof => "proof",
             SemanticType::Attestation => "attestation",
+            SemanticType::Requirement => "requirement",
+            SemanticType::Decision => "decision",
+            SemanticType::Cost => "cost",
             SemanticType::Unknown => "unknown",
         }
     }
@@ -690,6 +699,9 @@ mod tests {
             SemanticType::Issue,
             SemanticType::Proof,
             SemanticType::Attestation,
+            SemanticType::Requirement,
+            SemanticType::Decision,
+            SemanticType::Cost,
             SemanticType::Unknown,
         ];
         for st in all {
@@ -816,6 +828,9 @@ mod tests {
             SemanticType::Issue,
             SemanticType::Proof,
             SemanticType::Attestation,
+            SemanticType::Requirement,
+            SemanticType::Decision,
+            SemanticType::Cost,
             SemanticType::Unknown,
         ];
         for st in all {

crates/ledger-core/src/iso_objects.rs

@@ -1,4 +1,4 @@
-//! `HasVisualization` implementations for the 28 domain types that participate
+//! `HasVisualization` implementations for the 31 domain types that participate
 //! in the isometric pipeline view.
 //!
 //! Every `impl HasVisualization` added here must also be registered in
@@ -469,9 +469,64 @@
     }
 }
 
+// ============================================================================
+// SYSTEMS MODEL — Requirement/Decision/Cost (z=6, SystemsModel layer)
+// ============================================================================
+
+#[cfg(feature = "arc-kit-au")]
+mod systems_model {
+    use arc_kit_au::node::{Cost, Decision, Requirement};
+
+    use crate::iso::{HasVisualization, RhaiDsl, SemanticType, VisualizationSpec, ZLayer};
+
+    impl HasVisualization for Requirement {
+        fn viz_spec() -> VisualizationSpec {
+            VisualizationSpec {
+                semantic_type: SemanticType::Requirement,
+                z_layer: ZLayer::SystemsModel,
+                rhai_dsl: RhaiDsl::new(
+                    r#"let req = load_requirement(source);
+if req.status == "active" { link_decisions(req.related_decisions) }"#,
+                ),
+                description: "SysML v2 systems-modeling requirement — traceable spec record, linked to the decisions it constrains",
+            }
+        }
+    }
+
+    impl HasVisualization for Decision {
+        fn viz_spec() -> VisualizationSpec {
+            VisualizationSpec {
+                semantic_type: SemanticType::Decision,
+                z_layer: ZLayer::SystemsModel,
+                rhai_dsl: RhaiDsl::new(
+                    r#"let decision = record_decision(subject, rationale, decided_by);
+link_requirements(decision.related_requirements);"#,
+                ),
+                description: "Version-controlled decision record — rationale + decider, linked back to the requirements it satisfies",
+            }
+        }
+    }
+
+    impl HasVisualization for Cost {
+        fn viz_spec() -> VisualizationSpec {
+            VisualizationSpec {
+                semantic_type: SemanticType::Cost,
+                z_layer: ZLayer::SystemsModel,
+                rhai_dsl: RhaiDsl::new(
+                    r#"let cost = record_cost(subject, amount, currency);
+if cost.related_decision.is_some() { attribute_to_decision(cost) }"#,
+                ),
+                description: "Version-controlled cost record — monetary amount attributed to a decision for systems-modeling cost traceability",
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+    #[cfg(feature = "arc-kit-au")]
+    use arc_kit_au::node::{Cost, Decision, Requirement};
 
     #[test]
     fn all_viz_spec_rhai_dsl_has_valid_syntax() {
@@ -517,6 +572,13 @@
         check!(UsRdcCredit);
         check!(CryptoTx);
         check!(CryptoWallet);
+        // Systems-modeling domain
+        #[cfg(feature = "arc-kit-au")]
+        {
+            check!(Requirement);
+            check!(Decision);
+            check!(Cost);
+        }
     }
 }
 

crates/ledgerr-mcp/tests/pipeline_e2e.rs

@@ -180,7 +180,7 @@ fn pipe_viz_manifest_entry_count_matches_registered_types() {
     // `impl HasVisualization` blocks in `ledger_core::iso_objects`. It must be
     // regenerated (and this count updated) whenever an impl is added, removed,
     // or registered/deregistered in xtask/src/viz_manifest.rs.
-    const EXPECTED_ENTRY_COUNT: usize = 28;
+    const EXPECTED_ENTRY_COUNT: usize = 31;
 
     let manifest_path = Path::new(env!("CARGO_MANIFEST_DIR"))
         .parent()
@@ -218,6 +218,9 @@ fn pipe_viz_manifest_entry_count_matches_registered_types() {
             "AuRdActivity",
             "UsRdcCredit",
             "CryptoWallet",
+            "Requirement",
+            "Decision",
+            "Cost",
         ] {
             assert!(names.contains(&expected), "missing {expected} entry");
         }