v1.2.3 - Improved scan accuracy, real sender blocking, and deletion options

• 2-phase subscription scan: Inbox and spam are now scanned separately for more complete results (Gmail limits results when using in:anywhere with keywords)
• Auto-switch from "Most relevant" to "Newest": Automatically disables Gmail's relevance filter that hides search results
• User alias detection: Detects your email aliases from the Sent folder to exclude your own emails from results
• Real sender blocking: When no safe unsubscribe button is found, the extension now uses Gmail's native "Block" feature (three-dot menu) to actually block the sender in Gmail, instead of only hiding them from the extension
• "Delete only read" option: When deleting emails, detects unread count and offers the choice to keep unread messages
• Filter explanation dialog: When unsubscribe falls back to blocking, shows an explanation with a "don't show again" option