stabilizaiton work - projects rework for maintenanceability and ui livening

src/__Libraries/StellaOps.ReachGraph.Persistence/PostgresReachGraphRepository.Delete.cs

@@ -0,0 +1,44 @@
+// Licensed to StellaOps under the BUSL-1.1 license.
+using Dapper;
+using Microsoft.Extensions.Logging;
+
+namespace StellaOps.ReachGraph.Persistence;
+
+public sealed partial class PostgresReachGraphRepository
+{
+    /// <inheritdoc />
+    public async Task<bool> DeleteAsync(
+        string digest,
+        string tenantId,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(digest);
+        ArgumentException.ThrowIfNullOrEmpty(tenantId);
+
+        await using var connection = await _dataSource
+            .OpenConnectionAsync(cancellationToken)
+            .ConfigureAwait(false);
+        await SetTenantContextAsync(connection, tenantId, cancellationToken).ConfigureAwait(false);
+
+        const string sql = """
+            DELETE FROM reachgraph.subgraphs
+            WHERE digest = @Digest
+              AND tenant_id = @TenantId
+            RETURNING digest
+            """;
+
+        var command = new CommandDefinition(
+            sql,
+            new { Digest = digest, TenantId = tenantId },
+            cancellationToken: cancellationToken);
+        var deleted = await connection.QuerySingleOrDefaultAsync<string>(command).ConfigureAwait(false);
+
+        if (deleted is not null)
+        {
+            _logger.LogInformation("Deleted reachability graph {Digest}", digest);
+            return true;
+        }
+
+        return false;
+    }
+}