Send reply mail from the post event bus (#16)

Stacks on #15. Handlers only persist and publish; a mail subscriber sends reply email. Unset Resend stays a no-op.

Reviewed-on: #16
Co-authored-by: codegirl-007 <s.raide@gmail.com>

internal/web/server.go

@@ -22,7 +22,6 @@ import (
 	"plumber/internal/blob"
 	"plumber/internal/events"
 	"plumber/internal/geo"
-	"plumber/internal/mail"
 	"plumber/internal/pacific"
 	"plumber/internal/store"
 )
@@ -35,7 +34,6 @@ type Config struct {
 	// TrustedProxies are CIDRs allowed to set X-Forwarded-For (direct peer).
 	TrustedProxies []*net.IPNet
 	Blob           blob.Uploader
-	Mail           mail.Notifier
 	Events         events.Publisher
 	BaseURL        string
 }
@@ -110,9 +108,6 @@ func New(st store.Store, sessionStore scs.Store, templateFS fs.FS, staticFS fs.F
 	if cfg.Blob == nil {
 		cfg.Blob = blob.Disabled{}
 	}
-	if cfg.Mail == nil {
-		cfg.Mail = mail.Nop{}
-	}
 	if cfg.Events == nil {
 		cfg.Events = events.Nop{}
 	}