Add PhotoUpload feature for uploading photos to file storage

Adds UploadPhotoCommand/Handler/Validator and PhotoUploadRepository, invoked via MediatR by other features' commands (e.g. a future CreateBreweryPhoto) rather than exposed through its own controller. Wires the feature and IFileStorageProvider into API.Core.

web/backend/Features/Features.PhotoUpload/Repository/PhotoUploadRepository.cs

@@ -0,0 +1,69 @@
+using System.Data.Common;
+using Dapper;
+using Database.Connection;
+using Domain.Entities;
+using Domain.Exceptions;
+
+namespace Features.ImageUploads.Repository;
+
+public interface IPhotoUploadRepository
+{
+    Task CreateAsync(Photo photo, CancellationToken cancellationToken);
+}
+
+public class PhotoUploadRepository(ISqlConnectionFactory connectionFactory)
+    : DapperRepository(connectionFactory),
+        IPhotoUploadRepository
+{
+    public async Task CreateAsync(Photo photo, CancellationToken cancellationToken)
+    {
+
+        await using DbConnection connection = await CreateConnection();
+        await using DbTransaction transaction = await connection.BeginTransactionAsync();
+
+        try
+        {
+            bool userExists =
+                await connection.ExecuteScalarAsync<int?>(
+                    new CommandDefinition(
+                        """
+                                    SELECT 1
+                                    FROM
+                                        dbo.UserAccount
+                                    WHERE
+                                        UserAccountID = @UploadedById
+                        """,
+                        new { photo.UploadedById },
+                        transaction
+                    )
+                )
+                is not null;
+
+            if (!userExists)
+                throw new NotFoundException("User not found.");
+
+            await connection.ExecuteAsync(
+                new CommandDefinition(
+                    """
+                    INSERT INTO dbo.Photo (Hyperlink, UploadedByID)
+                    VALUES (@Hyperlink, @UploadedById)
+                    """,
+                    new
+                    {
+                        photo.Hyperlink,
+                        photo.UploadedById
+                    },
+                    transaction
+                )
+            );
+
+            await transaction.CommitAsync(cancellationToken);
+        }
+        catch
+        {
+            await RollbackQuietlyAsync(transaction);
+            throw;
+        }
+    }
+
+}