The sticky <thead> jumped up ~8px and picked up the scroller's top fade
the moment you scrolled 1px — so it read as 'not fixed'. Two causes:
- the table sat under a pt-2 gap, so its natural position was 8px below
the sticky top:0 it snapped to. Drop the top padding (the fixed band's
controls row already gives the visual gap) → no shift.
- the page scroller's top edge fade turned on with the first scroll and
masked the header's top. Add a fadeTop flag (PageShell → PageScroller →
useScrollFade), off for the Channels + Audit pages whose scroll region
starts with a sticky header. Feed/channel keep the top fade (it fades
cards under the fixed toolbar, as intended).
Verified: header stays at a fixed offset with no fade change from scroll 0
through scrolled, on both the manager and the audit log. Suite 15/15.
Generalise the fixed-chrome pattern to the channel detail page: the
banner + identity now scroll away, while the tab row and the channel
feed's toolbar stick to the top as a sticky sub-header — only the video
grid scrolls.
Mechanism: PageToolbarSlot (the toolbar portal target) is now an exported,
overridable context. ChannelPage provides its own sticky sub-header node
as the target, so the channelScoped Feed portals its toolbar up next to
the tabs instead of into the shell's top band. Feed always portals its
toolbar now (the slot decides where it lands).
Also: the page scroller now fades only its BOTTOM edge — the top is
bounded by the fixed/sticky chrome, so a top fade only bit into it.
E2E: adds a lock that the channel tabs/toolbar stay pinned while the
banner scrolls away; suite 15/15 on :5173, tsc + knip clean.
The shell owns the scroller, so it owns the scroll policy. PageScroller
now takes a scrollKey identifying the logical view and keeps a per-view
offset in a module-level map, recorded live on scroll:
- same key returning (feed -> channel -> Back, filters unchanged) restores
where you were (bug 1) -- the feed's scroller unmounts, but the saved
offset survives and is re-applied, retried over a few frames so the
virtualized list has time to reach its full height;
- a new key (feed filters changed) starts at the top of the fresh result
set (bug 3). q is normalised out of the feed key so typing doesn't reset.
Recording on scroll rather than at unmount matters: by cleanup time the
scroller's scrollTop is already zeroed, so a cleanup-read saved 0.
Also fixes a Maximum-update-depth loop this introduced: the combined
element/fade ref was an inline callback, so React re-attached it every
commit and re-ran useScrollFade's state setter. Bound it with useCallback.
Adds E2E locks for bugs 1, 3 and 4 (restore on Back, reset on filter,
toolbar stays pinned). Full suite 14/14 green on :5173; tsc + knip clean.
The feed's show/content chips, source, count, sort and view switcher —
plus the active-filter chips — lived inside the scroller, so they
scrolled away with the cards; only the SearchBar strip stayed fixed.
Give PageShell a fixed toolbar band (filled by a module via the new
PageToolbar portal) above the scroller. On the feed page the toolbar +
chips portal into it and stay put — and removable — while cards scroll.
The channel-embedded Feed (channelScoped) keeps its inline toolbar,
which rides with the banner/tabs as before.
Verified both entry points at desktop + 1000px (toolbar wraps in-flow,
band grows, still pinned); E2E 11/11; tsc + knip clean.
Collapse App's hand-assembled normal-page chrome (floating Header +
top-padded wrapper + PageScroller + banners) into a single PageShell
contract with declared fixed vs scrollable regions. No behaviour change;
the channel page still renders its own scroller (dissolved next).
Groundwork for the S4 fixed-chrome/scroll-ownership seam.
peter