feat(emv2): error-propagation traversal across AADL connection graph (v0.10.x)

artifacts/requirements.yaml

@@ -2036,6 +2036,23 @@ artifacts:
     status: implemented
     tags: [mermaid, cli, v0100]
 
+  - id: REQ-EMV2-PROPAGATION-001
+    type: requirement
+    title: EMV2 error-propagation traversal across AADL connection graph
+    description: >
+      spar shall provide an analysis pass that, for each component declaring
+      an `out propagation` for an error type T, walks the AADL connection
+      graph (via semantic connections) to identify all downstream components
+      that declare a matching `in propagation` for T (case-insensitive match
+      per AADL EMV2 v2 §4.3).  The traversal shall recurse transitively
+      through relay components that declare both in and out propagations for
+      the same type.  Cycle detection (tracking component+error_type pairs)
+      shall prevent infinite loops in cyclic topologies.  Error flows
+      (path/sink/source) shall be captured per component in the report but
+      shall not by themselves trigger cross-component propagation.
+    status: implemented
+    tags: [emv2, analysis, v0100, safety]
+
   # ── CI / Verification gate ──────────────────────────────────────────────
 
   - id: REQ-VERIFY-GATE-001

artifacts/verification.yaml

@@ -2648,6 +2648,30 @@ artifacts:
       - type: satisfies
         target: REQ-MERMAID-CLI-001
 
+  - id: TEST-EMV2-PROPAGATION
+    type: feature
+    title: EMV2 error-propagation traversal tests
+    description: >
+      Unit tests in crates/spar-analysis/src/emv2_propagation.rs verify:
+      (a) single-hop propagation produces one chain (sensor → controller)
+      with the correct origin, error type, downstream, and via-connection;
+      (b) three-hop chain A→B→C→D with relay nodes produces downstream in
+      order [B, C, D]; (c) cycle detection (A→B→A) terminates cleanly with
+      each origin's chain not containing the origin itself; (d) path error
+      flows appear in local_flows but produce no propagation chain;
+      (e) case-insensitive error-type matching yields a chain despite
+      differing capitalisation; (f) no connection between components with
+      matching propagations yields no chain.
+    fields:
+      method: automated-test
+      steps:
+        - run: cargo test -p spar-analysis emv2_propagation
+    status: passing
+    tags: [emv2, analysis, v0100, safety]
+    links:
+      - type: satisfies
+        target: REQ-EMV2-PROPAGATION-001
+
   # ── CI / Verification gate ──────────────────────────────────────────────
 
   - id: TEST-VERIFY-GATE-RUNNER