Computed alarms place as leaves at their path-qualified AlarmName; native conditions group under a deduped IsNativeBinding branch keyed by NativeSourceCanonicalName with condition children keyed canonical::sourceRef. Configured-placeholder events materialise a childless binding node. Alarm roll-up (WorstState/ActiveCount) excludes placeholders. Filter matches AlarmName/SourceReference/NativeSourceCanonicalName (OrdinalIgnoreCase) and retains ancestor + binding branches. 20 new TDD cases; 18 attribute cases stay green. No DebugTreeNode model changes.
Fix 1 (Important): RollUp_FourLevelDeepBadQuality_ReachesRoot — proves bad quality at a
4-segment-deep leaf propagates HasBadQuality up every ancestor to the root.
Fix 2 (Important): Filter_DeepLeafMatch_RetainsAllAncestorBranches — proves filtering on
a terminal segment of a 3-level path retains all ancestor branches.
Fix 3 (Minor): BuildAttributeTree now returns roots.AsReadOnly() so the returned
IReadOnlyList<DebugTreeNode> reference is not a mutable list.
Fix 4 (Minor): Added <remarks> XML doc to BuildAttributeTree noting the caller-contract
that at most one AttributeValueChanged per AttributeName should be passed.
All 18 DebugTreeBuilder tests pass.
Pure path-split composition forest from streamed AttributeValueChanged: branch dedupe by accumulated prefix, ordinal child sort, post-order bad-quality roll-up, case-insensitive name-contains filter (keeps ancestors). BuildAlarmTree left as a NotImplementedException stub for DV-4. 16 unit tests cover structure + roll-up + filter.
Joseph Doherty