Potential experiments

perf(app): play gif embeds from the viewport not a js decoder (#1877)

feat(app): warm full-size media while hovering an attachment (#1876)

fix(app): stop overlaying a sharpening canvas in the media viewer (#1875)

fix(app): stop seeking and hidden tabs from stranding playback (#1874)

fix(app): size youtube embeds with the shared embed limits (#1873)

feat(app): drop the compact attachments media size preference (#1872)

fix(app): contain embedded media inside its box instead of overflowing (#1871)

perf(app): window emoji picker rows by offset instead of observers (#1870)

fix(app): animate message emoji only while hovering the message (#1869)

fix(app): draw the mention badge cutout from the badge itself (#1868)

fix(app): stop animating emoji and stickers that have no animation (#1867)

fix(app): stop discovery animating on first render (#1866)

perf(app): fetch text attachment previews only when they scroll near (#1865)

fix(app): only animate media that has an animated variant (#1864)

fix(app): scope near-viewport loading to the surrounding scroller (#1863)

fix(app): scope near-viewport loading to the surrounding scroller

fix(app): keep hydrated state across gateway session resumes (#1862)

fix(app): keep unsent messages and stop the unread jump on reconnect (#1861)

fix(app): keep the chat scroller pinned to the end while it resizes (#1860)

refactor(app): name mute and unread state accessors by intent (#1859)