{
  "planPath": "docs/plans/2026-06-18-galaxy-writer-handle-sharing.md",
  "designPath": "docs/plans/2026-06-18-galaxy-writer-handle-sharing-design.md",
  "designCommit": "c85c4e5c",
  "baseMaster": "70e1bde9",
  "branch": "feat/galaxy-writer-handle-sharing",
  "scope": "Galaxy writer borrows live MXAccess item handles from the SubscriptionRegistry so the first write to an already-subscribed tag skips a redundant AddItem round-trip. T1: SubscriptionRegistry.TryResolveItemHandle forward fullRef->handle lookup with a liveness guard. T2: writer optional Func<string,int?> subscribedHandleSource + TryResolveCachedOrBorrowed seam (borrowed handles NOT cached) + AddItemCallCount seam. T3: GalaxyDriver wires _subscriptions.TryResolveItemHandle into the production writer ctor. T4: skip-gated live-gw smoke proving a subscribed-tag write commits with AddItemCallCount==0 (control: ==1). NO Commons/proto/EF/migration change; NO bUnit; AdminUI untouched.",
  "dependencyGraph": "{T1 ∥ T2} -> T3 -> T4",
  "tasks": [
    {"id": 1, "subject": "SubscriptionRegistry.TryResolveItemHandle forward lookup + tests", "classification": "small", "status": "pending", "parallelizableWith": [2], "files": ["src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/SubscriptionRegistry.cs", "tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/SubscriptionRegistryHandleResolveTests.cs"]},
    {"id": 2, "subject": "Writer borrow seam + AddItemCallCount + tests", "classification": "small", "status": "pending", "parallelizableWith": [1], "files": ["src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GatewayGalaxyDataWriter.cs", "tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/GatewayGalaxyDataWriterTests.cs"]},
    {"id": 3, "subject": "Wire registry resolver into the production writer in GalaxyDriver", "classification": "small", "status": "pending", "blockedBy": [1, 2], "files": ["src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs"]},
    {"id": 4, "subject": "Live-gw borrow smoke + build/test + live run + finish", "classification": "small", "status": "pending", "blockedBy": [3], "files": ["tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/GatewayGalaxyLiveReopenAndWriteTests.cs"]}
  ],
  "executionState": "PENDING — subagent-driven execution, this session.",
  "lastUpdated": "2026-06-18"
}