#5: F2 sub-project 2 - IMAP SEARCH, EXPUNGE, COPY, MOVE

Adds the second F2 sub-project on top of the merged IMAP core: full
SEARCH criteria matching (flags, dates, size, headers, body/text,
NOT/OR), EXPUNGE (soft-delete via expunged_at), COPY, and MOVE (RFC
6851, advertised via CapMove/CapUIDPlus). Verified end-to-end with a
real go-imap/v2 client against embedded Postgres.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

services/protocols/internal/infrastructure/postgres/copy_repository_test.go

@@ -0,0 +1,110 @@
+package postgres
+
+import (
+	"context"
+	"testing"
+
+	"github.com/google/uuid"
+	"lambdamail/protocols/internal/application/port"
+)
+
+func TestCopyRepository_CopyMessages_AllocatesNewUIDsAndPreservesFlags(t *testing.T) {
+	pool := testPool(t)
+	defer pool.Close()
+	ctx := context.Background()
+
+	domainID := uuid.New()
+	domainName := "copyrepo-test-" + domainID.String() + ".invalid"
+	_, err := pool.Exec(ctx, `INSERT INTO domains (id, name, punycode_name) VALUES ($1, $2, $3)`,
+		domainID, domainName, domainName)
+	if err != nil {
+		t.Fatalf("seed domain: %v", err)
+	}
+	defer pool.Exec(ctx, `DELETE FROM domains WHERE id = $1`, domainID)
+
+	mailboxID := uuid.New()
+	_, err = pool.Exec(ctx, `INSERT INTO mailboxes (id, domain_id, local_part, email_address, password_hash) VALUES ($1, $2, 'user', $3, '$argon2id$v=19$m=65536,t=3,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG')`,
+		mailboxID, domainID, "user@"+domainName)
+	if err != nil {
+		t.Fatalf("seed mailbox: %v", err)
+	}
+	sourceFolderID := uuid.New()
+	_, err = pool.Exec(ctx, `INSERT INTO folders (id, mailbox_id, name, special_use) VALUES ($1, $2, 'INBOX', 'inbox')`,
+		sourceFolderID, mailboxID)
+	if err != nil {
+		t.Fatalf("seed source folder: %v", err)
+	}
+	destFolderID := uuid.New()
+	_, err = pool.Exec(ctx, `INSERT INTO folders (id, mailbox_id, name) VALUES ($1, $2, 'Archive')`,
+		destFolderID, mailboxID)
+	if err != nil {
+		t.Fatalf("seed dest folder: %v", err)
+	}
+	blobID := uuid.New()
+	_, err = pool.Exec(ctx, `INSERT INTO message_blobs (id, content_sha256, storage_driver, storage_path, size_bytes, ref_count) VALUES ($1, $2, 'local', '/tmp/x', 10, 1)`,
+		blobID, uuid.New().String()+uuid.New().String()[:32])
+	if err != nil {
+		t.Fatalf("seed blob: %v", err)
+	}
+	const sourceSubject = "Original subject line"
+	var sourceMessageID string
+	if err := pool.QueryRow(ctx, `
+		INSERT INTO email_messages (mailbox_id, folder_id, uid, blob_id, sender_address, recipient_addresses, size_bytes, subject)
+		VALUES ($1, $2, 5, $3, 'sender@example.test', $4, 10, $5) RETURNING id
+	`, mailboxID, sourceFolderID, blobID, []string{"user@" + domainName}, sourceSubject).Scan(&sourceMessageID); err != nil {
+		t.Fatalf("seed source message: %v", err)
+	}
+	if _, err := pool.Exec(ctx, `
+		INSERT INTO message_flags (message_id, received_at, flag)
+		SELECT id, received_at, '\Seen' FROM email_messages WHERE id = $1
+	`, sourceMessageID); err != nil {
+		t.Fatalf("seed source flag: %v", err)
+	}
+
+	repo := NewCopyRepository(pool)
+	copied, err := repo.CopyMessages(ctx, sourceFolderID.String(), []uint32{5}, destFolderID.String())
+	if err != nil {
+		t.Fatalf("CopyMessages: %v", err)
+	}
+	if len(copied) != 1 || copied[0].SourceUID != 5 || copied[0].DestUID != 1 {
+		t.Fatalf("copied = %+v, want [{SourceUID:5 DestUID:1}]", copied)
+	}
+
+	var destCount int
+	if err := pool.QueryRow(ctx, `SELECT count(*) FROM email_messages WHERE folder_id = $1`, destFolderID).Scan(&destCount); err != nil {
+		t.Fatalf("count dest messages: %v", err)
+	}
+	if destCount != 1 {
+		t.Fatalf("dest folder has %d messages, want 1", destCount)
+	}
+
+	var destFlagCount int
+	if err := pool.QueryRow(ctx, `
+		SELECT count(*) FROM message_flags mf
+		JOIN email_messages m ON m.id = mf.message_id AND m.received_at = mf.received_at
+		WHERE m.folder_id = $1 AND mf.flag = '\Seen'
+	`, destFolderID).Scan(&destFlagCount); err != nil {
+		t.Fatalf("count dest flags: %v", err)
+	}
+	if destFlagCount != 1 {
+		t.Errorf("dest message has %d \\Seen flags, want 1 (flags must be preserved on copy)", destFlagCount)
+	}
+
+	var destSubject *string
+	if err := pool.QueryRow(ctx, `SELECT subject FROM email_messages WHERE folder_id = $1`, destFolderID).Scan(&destSubject); err != nil {
+		t.Fatalf("query dest subject: %v", err)
+	}
+	if destSubject == nil || *destSubject != sourceSubject {
+		t.Errorf("dest subject = %v, want %q (subject must be preserved on copy)", destSubject, sourceSubject)
+	}
+
+	var refCount int
+	if err := pool.QueryRow(ctx, `SELECT ref_count FROM message_blobs WHERE id = $1`, blobID).Scan(&refCount); err != nil {
+		t.Fatalf("query ref_count: %v", err)
+	}
+	if refCount != 2 {
+		t.Errorf("ref_count = %d, want 2 (1 original + 1 copy referencing the same blob)", refCount)
+	}
+
+	_ = port.CopiedMessage{} // keep the port import used if the assertions above change
+}