Client rename residuals: lmxopcua-cli → otopcua-cli + LmxOpcUaClient → OtOpcUaClient with migration shim. Closes task #208 (the executable-name + LocalAppData-folder slice that was called out in Client.CLI.md / Client.UI.md as a deliberately-deferred residual of the Phase 0 rename). Six source references flipped to the canonical OtOpcUaClient spelling: Program.cs CliFx executable name + description (lmxopcua-cli → otopcua-cli), DefaultApplicationConfigurationFactory.cs ApplicationName + ApplicationUri (LmxOpcUaClient + urn:localhost:LmxOpcUaClient → OtOpcUaClient + urn:localhost:OtOpcUaClient), OpcUaClientService.CreateSessionAsync session-name arg, ConnectionSettings.CertificateStorePath default, MainWindowViewModel.CertificateStorePath default, JsonSettingsService.SettingsDir. Two consuming tests (ConnectionSettingsTests + MainWindowViewModelTests) updated to assert the new canonical name. New ClientStoragePaths static helper at src/ZB.MOM.WW.OtOpcUa.Client.Shared/ClientStoragePaths.cs is the migration shim — single entry point for the PKI root + pki subpath, runs a one-shot legacy-folder probe on first resolution: if {LocalAppData}/LmxOpcUaClient/ exists + {LocalAppData}/OtOpcUaClient/ does not, Directory.Move renames it in place (atomic on NTFS within the same volume) so trusted server certs + saved connection settings persist across the rename without operator action. Idempotent per-process via a Lock-guarded _migrationChecked flag so repeated CertificateStorePath getter calls on the hot path pay no IO cost beyond the first. Fresh-install path (neither folder exists) + already-migrated path (only canonical exists) + manual-override path (both exist — developer has set up something explicit) are all no-ops that leave state alone. IOException on the Directory.Move is swallowed + logged as a false return so a concurrent peer process losing the race doesn't crash the consumer; the losing process falls back to whatever state exists. Five new ClientStoragePathsTests assert: GetRoot ends with canonical name under LocalAppData, GetPkiPath nests pki under root, CanonicalFolderName is OtOpcUaClient, LegacyFolderName is LmxOpcUaClient (the migration contract — a typo here would leak the legacy folder past the shim), repeat invocation returns false after first-touch arms the in-process guard. Doc-side residual-explanation notes in docs/Client.CLI.md + docs/Client.UI.md are dropped now that the rename is real; replaced with a short "pre-#208 dev boxes migrate automatically on first launch" note that points at ClientStoragePaths. Sample CLI invocations in Client.CLI.md updated via sed from lmxopcua-cli to otopcua-cli across every command block (14 replacements). Pre-existing staleness in SubscribeCommandTests.Execute_PrintsSubscriptionMessage surfaced during the test run — the CLI's subscribe command has long since switched to an aggregate "Subscribed to {count}/{total} nodes (interval: ...)" output format but the test still asserted the original single-node form. Updated the assertion to match current output + added a comment explaining the change; this is unrelated to the rename but was blocking a green Client.CLI.Tests run. Full solution build 0 errors; Client.Shared.Tests 136/136 + 5 new shim tests passing; Client.UI.Tests 98/98; Client.CLI.Tests 52/52 (was 51/52 before the subscribe-test fix). No Admin/Core/Server changes — this touches only the client layer.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/Client.UI.md

@@ -65,7 +65,7 @@ The top bar provides the endpoint URL, Connect, and Disconnect buttons. The **Co
 
 ### Settings Persistence
 
-Connection settings are saved to `{LocalAppData}/LmxOpcUaClient/settings.json` after each successful connection and on window close. The folder name is a residual from the pre-v2 rename (the `Client.Shared` session factory still calls itself `LmxOpcUaClient` at `OpcUaClientService.cs:428`); renaming to `OtOpcUaClient` is a follow-up that needs a migration shim so existing users don't lose their settings on upgrade. The settings are reloaded on next launch, including:
+Connection settings are saved to `{LocalAppData}/OtOpcUaClient/settings.json` after each successful connection and on window close. Dev boxes upgrading from a pre-task-#208 build still have the legacy `LmxOpcUaClient/` folder on disk; `ClientStoragePaths` in `Client.Shared` moves it to the canonical path on first launch so existing trusted certs + saved settings persist without operator action. The settings are reloaded on next launch, including:
 
 - All connection parameters
 - Active subscription node IDs (restored after reconnection)