Bug Fixes
Mailto unsubscribe no longer opens a broken tab. tabs.create() cannot navigate to mailto: URIs inside extensions. The extension now parses the mailto link and opens a pre-filled Gmail compose window instead.
HTTP unsubscribe status is now accurate. Requests use mode: no-cors, which returns an opaque response where success and failure are indistinguishable. Status is now reported as SENT rather than the incorrect SUCCESS.
Native Gmail unsubscribe errors are no longer lost. If clicking Gmail's own unsubscribe button fails and a URL-based unsubscribe succeeds (or vice versa), both outcomes are now tracked and reported independently.
Unsubscribe button no longer appears on ordinary emails. The selector span[role="link"] matched almost any inline link in Gmail, causing false positives. It is now removed; detection is scoped to Gmail's data-tooltip unsubscribe elements only.
Whitelisted badge in popup had incorrect CSS class. tab_opened corrected to whitelisted.

Improvements
Retry after a failed attempt is now possible. Any logged attempt (including failed ones) for a given sender and URL previously blocked all future log entries. Re-logging is only blocked when a MAILTO action has already been taken for the same sender and URL.
MutationObserver scoped to Gmail's main panel. The observer targets [role="main"] instead of document.body, reducing unnecessary triggers from compose-window keystrokes and unrelated DOM activity.
Active Gmail tab preferred for search. When triggering a Gmail search from the popup with multiple Gmail tabs open, the extension now focuses the currently active tab rather than always picking the first one.
History entry IDs use crypto.randomUUID(). Date.now() was not collision-safe under concurrent batch unsubscribes.
Email extraction regex tightened. The TLD character class no longer permits dots, underscores, or hyphens, and requires a minimum of two alphabetic characters.

Initial release. Detects unsubscription links in open Gmail messages and Gmail search results, injects inline Unsubscribe action buttons, and provides a popup UI with batch unsubscription, sender whitelisting, custom Gmail search queries, unsubscription history, and CSV/JSON log export. All data is stored locally via browser.storage.local. No accounts, servers, or external data transmission involved.