Site Marker

Mark any site's domain with a label (Fraud / Scam / Suspicious / Note) plus a free-text reason. Next time you land on that domain, a red banner appears on the page and the toolbar icon gets a badge.

• Click the toolbar icon on any site to mark it
• Pick a label, optionally add a note, click "Mark site"
• Revisit that domain later -> red banner + badge shows up automatically
• Click the icon again to remove a mark, or manage the full list

• Matching is by hostname, not full URL. Marking example.com flags every page under that domain, including subpaths. This is deliberate — fraud sites are rarely worth remembering at the URL level.
• Two storage backends, chosen per-save via radio buttons:
• Local — browser.storage.local with the unlimitedStorage permission, capped only by disk space. Stays on this machine.
• Sync — browser.storage.sync, tied to your Firefox Account. Each site is stored under its own key (site:<hostname>), not one big blob, because sync caps each individual item at 8,192 bytes separately from the 100KB total quota — one key per site lets your list fill the full 100KB instead of hitting a wall around 20-30 sites.
• The radio only decides where the next save goes. Toggling it does not move marks you already saved under the other backend — a site keeps living wherever it was last saved until you open its popup and click "Mark site" again with the other radio selected. The list at the bottom tags each site local or sync so you can see where it actually is.
• Reading/checking a site (the banner, the badge, pre-filling the popup) always checks both backends, so nothing disappears just because the radio is on the "wrong" setting.
• Notes are capped at 280 characters, enforced in the textarea and in code.
• Both radio labels show live numbers (getBytesInUse / QUOTA_BYTES): local shows KB used so far, sync shows KB free out of 100KB.
• storage.sync also throttles writes: roughly 120/minute and 1800/hour in Firefox. Irrelevant for occasional manual marking, but don't wire this up to anything that marks sites automatically and rapidly.
• storage.sync silently behaves like local-only storage if you aren't signed into a Firefox Account under Sync — no error is thrown.
• The banner injection silently no-ops on privileged pages (about:, addons.mozilla.org, etc.) — Firefox blocks content-script injection there regardless of permissions