feat: allow sign in with email (#100)

backend/internal/service/email_service_templates.go

@@ -9,7 +9,7 @@ import (
 /**
 How to add new template:
 - pick unique and descriptive template ${name} (for example "login-with-new-device")
-- in backend/email-templates/ create "${name}_html.tmpl" and "${name}_text.tmpl"
+- in backend/resources/email-templates/ create "${name}_html.tmpl" and "${name}_text.tmpl"
 - create xxxxTemplate and xxxxTemplateData (for example NewLoginTemplate and NewLoginTemplateData)
   - Path *must* be ${name}
 - add xxxTemplate.Path to "emailTemplatePaths" at the end
@@ -27,6 +27,13 @@ var NewLoginTemplate = email.Template[NewLoginTemplateData]{
 	},
 }
 
+var OneTimeAccessTemplate = email.Template[OneTimeAccessTemplateData]{
+	Path: "one-time-access",
+	Title: func(data *email.TemplateData[OneTimeAccessTemplateData]) string {
+		return "One time access"
+	},
+}
+
 var TestTemplate = email.Template[struct{}]{
 	Path: "test",
 	Title: func(data *email.TemplateData[struct{}]) string {
@@ -42,5 +49,9 @@ type NewLoginTemplateData struct {
 	DateTime  time.Time
 }
 
+type OneTimeAccessTemplateData = struct {
+	Link string
+}
+
 // this is list of all template paths used for preloading templates
-var emailTemplatesPaths = []string{NewLoginTemplate.Path, TestTemplate.Path}
+var emailTemplatesPaths = []string{NewLoginTemplate.Path, OneTimeAccessTemplate.Path, TestTemplate.Path}