refactor: rename ScadaLink → ZB.MOM.WW.ScadaBridge (code + projects + namespaces)

Solution + 23 src projects + 26 test projects renamed; folders, csproj,
namespaces, and ScadaLinkDbContext/ScadaBridgeDbContext class updated.
ActorSystem "scadalink" → "scadabridge", Akka seed-node URLs migrated.
SQL roles/logins, LDAP domains, CLI command name, and CLI config dir
(~/.scadalink → ~/.scadabridge) also renamed.

Build green; 5 Host.Tests fail awaiting SQL login rename in next commit.
Pre-existing StaleTagMonitor timing flakes unchanged.

Rename script committed at tools/rename-to-scadabridge.sh.

tests/ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests/OperationLockManagerTests.cs

@@ -0,0 +1,143 @@
+namespace ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests;
+
+/// <summary>
+/// WP-3: Tests for per-instance operation lock.
+/// </summary>
+public class OperationLockManagerTests
+{
+    private readonly OperationLockManager _lockManager = new();
+
+    [Fact]
+    public async Task AcquireAsync_ReturnsDisposable()
+    {
+        using var lockHandle = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        Assert.NotNull(lockHandle);
+    }
+
+    [Fact]
+    public async Task AcquireAsync_SameInstance_BlocksSecondCaller()
+    {
+        using var firstLock = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+
+        // Second acquire should time out
+        await Assert.ThrowsAsync<TimeoutException>(() =>
+            _lockManager.AcquireAsync("inst1", TimeSpan.FromMilliseconds(50)));
+    }
+
+    [Fact]
+    public async Task AcquireAsync_DifferentInstances_BothSucceed()
+    {
+        using var lock1 = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        using var lock2 = await _lockManager.AcquireAsync("inst2", TimeSpan.FromSeconds(5));
+
+        Assert.NotNull(lock1);
+        Assert.NotNull(lock2);
+    }
+
+    [Fact]
+    public async Task AcquireAsync_AfterRelease_CanReacquire()
+    {
+        var firstLock = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        firstLock.Dispose();
+
+        // Should succeed now
+        using var secondLock = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        Assert.NotNull(secondLock);
+    }
+
+    [Fact]
+    public async Task IsLocked_ReturnsTrueWhileLocked()
+    {
+        Assert.False(_lockManager.IsLocked("inst1"));
+
+        using var lockHandle = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        Assert.True(_lockManager.IsLocked("inst1"));
+    }
+
+    [Fact]
+    public async Task IsLocked_ReturnsFalseAfterRelease()
+    {
+        var lockHandle = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        lockHandle.Dispose();
+
+        Assert.False(_lockManager.IsLocked("inst1"));
+    }
+
+    [Fact]
+    public async Task AcquireAsync_DoubleDispose_DoesNotThrow()
+    {
+        var lockHandle = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(5));
+        lockHandle.Dispose();
+        lockHandle.Dispose(); // Should not throw
+    }
+
+    [Fact]
+    public async Task AcquireAsync_CancellationToken_Respected()
+    {
+        using var firstLock = await _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(30));
+
+        using var cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(50));
+        await Assert.ThrowsAnyAsync<OperationCanceledException>(() =>
+            _lockManager.AcquireAsync("inst1", TimeSpan.FromSeconds(30), cts.Token));
+    }
+
+    [Fact]
+    public async Task AcquireAsync_ConcurrentDifferentInstances_AllSucceed()
+    {
+        var tasks = Enumerable.Range(0, 10).Select(async i =>
+        {
+            using var lockHandle = await _lockManager.AcquireAsync($"inst{i}", TimeSpan.FromSeconds(5));
+            await Task.Delay(10);
+        });
+
+        await Task.WhenAll(tasks);
+    }
+
+    // ── DeploymentManager-005: semaphore must not leak ──
+
+    [Fact]
+    public async Task AcquireAsync_ReleasedLock_RemovesSemaphoreEntry()
+    {
+        // A semaphore that is created, used, and fully released must not be
+        // retained — otherwise every distinct instance name leaks a
+        // SemaphoreSlim (a kernel handle) for the life of the process.
+        using (await _lockManager.AcquireAsync("transient-inst", TimeSpan.FromSeconds(5)))
+        {
+            Assert.Equal(1, _lockManager.TrackedLockCount);
+        }
+
+        // After release, the entry is reclaimed.
+        Assert.Equal(0, _lockManager.TrackedLockCount);
+    }
+
+    [Fact]
+    public async Task AcquireAsync_ManyDistinctInstances_DoesNotAccumulateSemaphores()
+    {
+        // Simulates the long-running central process: many instances are
+        // deployed/disabled over time. Their semaphores must be reclaimed.
+        for (var i = 0; i < 100; i++)
+        {
+            using var handle = await _lockManager.AcquireAsync($"churn-{i}", TimeSpan.FromSeconds(5));
+        }
+
+        Assert.Equal(0, _lockManager.TrackedLockCount);
+    }
+
+    [Fact]
+    public async Task AcquireAsync_ContendedLock_KeepsSemaphoreUntilLastReleaseThenReclaims()
+    {
+        // While a second caller is waiting, the semaphore must survive the
+        // first release; only when the last holder releases is it reclaimed.
+        var first = await _lockManager.AcquireAsync("contended", TimeSpan.FromSeconds(5));
+
+        var secondAcquire = _lockManager.AcquireAsync("contended", TimeSpan.FromSeconds(5));
+
+        first.Dispose(); // hands the lock to the waiter; entry must NOT be removed
+        var second = await secondAcquire;
+
+        Assert.Equal(1, _lockManager.TrackedLockCount);
+        second.Dispose();
+
+        Assert.Equal(0, _lockManager.TrackedLockCount);
+    }
+}