code-reviews: resolve Server-059/060 + Tests-041 (fixed in 9ae6bce)

Dashboard Galaxy summary now copies volatile fields fresh and memoizes only the
O(N) breakdown; added the DI registration-order wiring test and the memoization
regression/guard tests. All modules back to 0 pending.

code-reviews/Tests/findings.md

@@ -7,7 +7,7 @@
 | Review date | 2026-06-25 |
 | Commit reviewed | `3cd7776` |
 | Status | Re-reviewed |
-| Open findings | 1 |
+| Open findings | 0 |
 
 ## Checklist coverage
 
@@ -789,7 +789,7 @@ The cancellation tests for `WorkerClient` in `WorkerClientTests` *do* exercise t
 | Severity | Medium |
 | Category | Testing coverage |
 | Location | `src/ZB.MOM.WW.MxGateway.Tests/Gateway/Dashboard/DashboardSnapshotServiceTests.cs`, `src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardSnapshotService.cs:109-128` |
-| Status | Open |
+| Status | Resolved |
 
 **Description:** `DashboardSnapshotService.ResolveGalaxySummary` introduced a lock-free
 memoization cache keyed on `GalaxyHierarchyCacheEntry.Sequence` (lines 109-128):
@@ -830,4 +830,4 @@ same `Sequence`. No test:
    `MutableGalaxyHierarchyCache` with a settable `Current` property suffices; the
    existing `StubGalaxyHierarchyCache` pattern is a single-line extension.
 
-**Resolution:**
+**Resolution:** Resolved in `9ae6bce` (2026-06-25). Added a `MutableGalaxyHierarchyCache` stub (settable `Current`) and three `DashboardSnapshotServiceTests` cases: `GetSnapshot_WhenGalaxyEntryChangesAtSameSequence_ReflectsVolatileStatusAndError` (the Server-059 regression), `GetSnapshot_WhenSequenceUnchanged_ReusesExpensiveTemplateBreakdown` (memoization hit — Objects swapped at the same `Sequence` stay frozen), and `GetSnapshot_WhenSequenceChanges_RecomputesTemplateBreakdown` (invalidation on `Sequence` change). The fix memoizes only the O(N) breakdown, so the assertions now target that rather than whole-summary identity.