feat: チャンネルに色を設定できるように

packages/backend/src/models/entities/Channel.ts

@@ -64,6 +64,12 @@ export class Channel {
 	})
 	public pinnedNoteIds: string[];
 
+	@Column('varchar', {
+		length: 16,
+		default: '#86b300',
+	})
+	public color: string;
+
 	@Index()
 	@Column('integer', {
 		default: 0,

packages/backend/src/models/json-schema/channel.ts

@@ -59,5 +59,9 @@ export const packedChannelSchema = {
 				format: 'id',
 			},
 		},
+		color: {
+			type: 'string',
+			optional: false, nullable: false,
+		},
 	},
 } as const;