Web Viewing Assist par 1llum1n4t1

A productivity helper that bundles 12 categories of features + partially supported Volume Booster into a single popup.

■ Features available on Firefox
🔹 Session Keep-alive
Dispatches synthesized activity events and same-origin HTTP pings to suppress auto-logout on intranet portals and admin dashboards. HTTP ping is opt-in (default OFF), uses 5-second AbortSignal timeout, same-origin only, redirect: manual to prevent credential leakage to third-party domains.

🔹 YouTube Cleaner (30 sub-features)
Remove search-result noise, Shorts removal (5 sub-features), watch-page tidying, comment/live-chat hiding, grid column count, subscription channel expansion (subs feed → grid + lazy thumbnail), and more granular controls for YouTube's verbose UI.

🔹 Amazon Subscribe & Save totals
On amazon.co.jp/auto-deliveries, computes per-month delivery totals and inserts them inline.

🔹 Amazon jump-to-ranking button
The bestseller-rank links in a product's detail section appear in different positions on every page and are hard to find, so this consolidates a "Go to this product's ranking" button at the top of the product info. Clicking it navigates (same tab) to the most specific subcategory ranking. Pure DOM manipulation, zero external transmission.

🔹 Amazon seller / shipper badge
Extracts the seller and shipper from the product page's hidden divs (#merchantInfoFeature_feature_div / #fulfillerInfoFeature_feature_div) and shows them as a "📦 Sold: XXX / Ships: YYY" badge at the top of the product info (right next to the jump-to-ranking button). Amazon-fulfilled and marketplace listings are visually distinguished (Amazon-fulfilled = green badge / marketplace = orange warning badge), making it easy to spot suspicious marketplace listings at a glance. The detection uses Amazon's own isInternal flag (embedded JSON in the <script> inside #merchantInfoFeature_feature_div) as the primary signal, with the seller name as a fallback. Pure DOM manipulation, zero external transmission.

🔹 Instagram Cleaner (11 sub-features)
Hides Reels / Explore / Stories / Threads / like counts / videos / comments / Notes / message counters, and similar verbose UI. Uses only semantic selectors (aria-label / role / data-pagelet); no dependency on obfuscated class names.

🔹 TikTok Cleaner (3 sub-features)
Hide comments / hide "Suggested accounts" / image download button.

🔹 Video Gamma
Global slider applies gamma correction to <video> elements (custom SVG <feComponentTransfer type="gamma"> implementation).

🔹 Remove video black bars
Removes the letterbox/pillarbox black bars on ultrawide screens by Zoom (aspect-preserving crop) or Stretch (expand only the deficient axis) to fill the screen. The video's aspect ratio is auto-detected; setting is shared across all tabs.

🔹 Loupe
Mouse-following circular magnifier. 3-step zoom / variable lens size. Uses tabs.captureVisibleTab so videos / iframes / canvases can also be magnified.

🔹 RTX Video Enhancer
Injects a 1×1 px invisible hint element on pages containing <video> elements to help GPU drivers (e.g., NVIDIA RTX Super Resolution / AMD FidelityFX) detect video pages. The driver-side feature itself must be enabled in the GPU settings (e.g., NVIDIA Control Panel). Zero external transmission.

🔹 Color Picker (popup tab)
EyeDropper API based. HEX / RGB / HSL formats with up to 20 history entries stored in browser.storage.local only (no external transmission).

🔹 Volume Booster (partial support — ordinary sites only)
Since v1.0.33, the Volume Booster is partially supported on Firefox. Ordinary video sites (YouTube / X / Twitch / TikTok / Instagram / niconico, etc.) are boosted via the content script's MediaElementSource path — the content script attaches directly to <video> / <audio> elements and applies automatically without ever opening the popup. Supports 0–300% amplification, auto distortion guard, auto volume normalization, night mode, and mute (master toggle + 3 sub-toggles + mute, all default OFF).
However, EME (DRM) heavy sites (Netflix / Prime Video / DAZN / Disney+ / Hulu / Apple TV+ / Spotify, etc. — 15 hosts) are unsupported on the Firefox edition. The Chrome edition can boost these sites via the chrome.tabCapture fallback path, but tabCapture is not supported by Firefox MV3. We plan to migrate to full support once Firefox implements the API.

■ Privacy
Fully local execution; zero external network calls. Only browser.storage.local is used (no sync / no cloud). See docs/privacy-policy.md for details.

■ Requirements
Firefox 142 or later.