feat(email): make verify-email org-aware like other transactional mail

Resolve the tenant org from the verification link callback URL (custom
domain, tenant subdomain, or ?org=) and apply org logo, theme color, from
name, and subject. Falls back to ClassroomIO branding on the main app.

Co-authored-by: Rotimi Best <[email protected]>

packages/email/src/send.ts

@@ -95,6 +95,7 @@ export async function sendEmail<TEmailId extends EmailId>(
       fields: validatedFields,
       from: config.from ?? template.from,
       replyTo: config.replyTo ?? template.replyTo,
+      subject: config.subject,
       ics: config.ics
     });
   } catch (error) {