Messaging · GIF picker: a GIF focused past the fold scrolls into view

Each GIF holds its own focus handle, and a canvas around it, ring and
all, sets the results box's offset once per focus from its painted
bounds. layout::bring_into_view now works along either axis; the data
table's header and the video timeline pass their sideways one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -92,7 +92,7 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - Only gpui can build `ExternalPaths` with paths, so drop rules live in `forms::files::dropped`, where tests reach them. `taken` adds file kinds by extension, for drops and the dialog alike (`DropZone::kinds`).
 - A stroke drawn with the pointer goes through `forms::pen`: a press starts it, a drag extends it, and the lift hands it over, in or out of the pad (`SignaturePad`, `generative::InpaintCanvas`).
 - gpui runs key bindings before key listeners. A container takes a child's bound key through the action with `capture_action`, as `Form` takes `Submit`.
-- `ScrollHandle::scroll_to_item` runs in the container's prepaint against last frame's bounds and overflow, so a call before a list's first frame does nothing. Call it from a child's prepaint once the handle has bounds, then request one frame (`navigation::editor_tabs`). A floating list reveals its cursor, and a strip its focused item, through `forms::options::reveal` and `revealer`. A focused Tab stop deeper in a scroll box sets the box's offset whole from its own painted bounds in prepaint, once per focus, through `layout::bring_into_view`. Never poll layout with `request_animation_frame`.
+- `ScrollHandle::scroll_to_item` runs in the container's prepaint against last frame's bounds and overflow, so a call before a list's first frame does nothing. Call it from a child's prepaint once the handle has bounds, then request one frame (`navigation::editor_tabs`). A floating list reveals its cursor, and a strip its focused item, through `forms::options::reveal` and `revealer`. A focused Tab stop deeper in a scroll box sets the box's offset whole from its own painted bounds in prepaint, once per focus, through `layout::bring_into_view` along the box's axis; the canvas measures the stop with its ring (`messaging::GifPicker`). Never poll layout with `request_animation_frame`.
 - gpui animations run on the wall clock; timers run on the executor's clock, which tests advance by hand. A test that needs an animation settled turns on the theme's reduced motion. Clocks read `background_executor().now()` and wake only their own view.
 - Machine-read marks, QR codes and barcodes, paint `ink` on `paper`: dark on light in both themes, so cameras read them.
 - A layer over pressable content that must still pass scrolls to its ancestors uses `block_mouse_except_scroll`; `occlude` hides them from scrolls too.