feat: add upgrade command

cli.ts

@@ -1,14 +1,34 @@
 import config from './deno.json' with { type: 'json' }
 import { Command } from '@cliffy/command'
+import { UpgradeCommand } from '@cliffy/command/upgrade'
+import { JsrProvider } from '@cliffy/command/upgrade/provider/jsr'
 import { cmd as send } from './cli/send.ts'
 import { cmd as preview } from './cli/preview.ts'
 
+const upgradeCommand = new UpgradeCommand({
+	args: [
+		'--allow-read',
+		'--allow-env',
+		'--allow-net=0.0.0.0',
+		'--allow-sys=osRelease,networkInterfaces',
+		'--allow-run=/usr/sbin/sendmail,whoami',
+		'--name=cohamail',
+	],
+	provider: [
+		new JsrProvider({
+			package: config.name as `@${string}/${string}`,
+			main: 'cli',
+		}),
+	],
+})
+
 const cli = new Command()
 	.name('cohamail')
 	.description('Mail cli for coh@bit.')
 	.version(config.version)
 	.command('preview', preview)
 	.command('send', send)
+	.command('upgrade', upgradeCommand)
 
 if (import.meta.main) {
 	if (Deno.args.length) {