feat: implement message deletion functionality and improve draft handling

- Added `MoveToTrash` method in `WebmailRepository` to move messages to the Trash folder instead of deleting them permanently.
- Introduced `handleDelete` method in `mailAPI` to handle message deletion requests from the client.
- Updated router to include a new route for message deletion.
- Enhanced the compose page to manage draft integrity, ensuring drafts are correctly associated with sent messages.
- Implemented UI changes to allow users to delete messages from the mail folder view.
- Added tests to verify the correct behavior of message deletion and draft handling.
- Updated database migration scripts to reconcile folder counters and ensure accurate unread counts.
- Added tests for TLS-RPT report parsing and webmail repository functionalities.

services/protocols/internal/application/port/inbound_message_repository.go

@@ -22,7 +22,12 @@ type PersistInboundMessageInput struct {
 	FromDisplayName string
 	MessageIDHeader string
 	HasAttachments  bool
-	SPFResult       string
+	// AlreadySeen marks a copy the user themselves composed - their own Sent
+	// copy, or a draft. It is not unread mail, and counting it as such is why
+	// the Sent folder carried an unread badge that nothing could clear: no
+	// reader ever opens their own outgoing copy, so the flag was never set.
+	AlreadySeen bool
+	SPFResult   string
 	DKIMResult      string
 	DMARCResult     string
 }

services/protocols/internal/application/port/webmail_repository.go

@@ -2,6 +2,7 @@ package port
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"github.com/google/uuid"
@@ -63,4 +64,16 @@ type WebmailRepository interface {
 	MarkSeen(ctx context.Context, mailboxID, folderName string, uid uint32, seen bool) error
 	// Expunge soft-deletes one message, keeping the folder counters in step.
 	Expunge(ctx context.Context, mailboxID, folderName string, uid uint32) error
+	// MoveToTrash relocates one message into Trash and returns its new UID
+	// there. This is what deleting a message means everywhere but in Trash
+	// itself, where Expunge is the operation instead.
+	MoveToTrash(ctx context.Context, mailboxID, folderName string, uid uint32) (uint32, error)
 }
+
+// ErrNoTrashFolder reports a mailbox with nowhere to put deleted mail, rather
+// than the message being destroyed instead.
+var ErrNoTrashFolder = errors.New("webmail: this mailbox has no Trash folder")
+
+// ErrAlreadyInTrash tells the caller to expunge rather than move: a message
+// already in Trash has no further destination.
+var ErrAlreadyInTrash = errors.New("webmail: message is already in Trash")