Move email/ resources to mail/, added invoice generated email to admin, updated email template

app/Mail/InvoiceGeneratedAdmin.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace App\Mail;
+
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Mail\Mailable;
+use Illuminate\Mail\Mailables\Content;
+use Illuminate\Mail\Mailables\Envelope;
+use Illuminate\Queue\SerializesModels;
+
+use App\Models\Invoice;
+
+class InvoiceGeneratedAdmin extends Mailable implements ShouldQueue
+{
+	use Queueable, SerializesModels;
+
+	protected Invoice $io;
+
+	/**
+	 * Create a new message instance.
+	 *
+	 * @param Invoice $o
+	 */
+	public function __construct(Invoice $o)
+	{
+		$this->io = $o;
+		$this->queue = 'admin';
+	}
+
+	/**
+	 * Get the message envelope.
+	 */
+	public function envelope(): Envelope
+	{
+		return new Envelope(
+			subject: sprintf('Invoice %d generated for %s, due %s',
+				$this->io->lid,
+				$this->io->account->name,
+				$this->io->due_at->format('Y-m-d')),
+		);
+	}
+
+	/**
+	 * Get the message content definition.
+	 */
+	public function content(): Content
+	{
+		return new Content(
+			markdown: 'mail.admin.invoice.generated',
+			with: [
+				'io'=>$this->io,
+				'site'=>$this->io->site,
+			]
+		);
+	}
+}