fix: rename "Copy credentials" to "Copy connection string"

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: karinakharchenko

frontend/src/app/components/connections-list/hosted-database-success-dialog/hosted-database-success-dialog.component.html

@@ -81,6 +81,6 @@ <h1 mat-dialog-title>
 		cdkFocusInitial
 		[cdkCopyToClipboard]="credentialsText"
 		(cdkCopyToClipboardCopied)="handleCredentialsCopied()">
-		Copy credentials
+		Copy connection string
 	</button>
 </mat-dialog-actions>