T25f Generative: data and prompts

DatasetViewer is tables::DataTable with row detail; the gallery pages
through a dataset and opens a sample whole. EmbeddingVisualizer scatters
points by group, flat or turned in three dimensions: lens.rs holds the
projection, where a turned view keeps the unit ball's scale and fits any
point past it at every turn. A drag or the arrow keys spin it, the
pointer names a point, and the legend hides a group. PromptPlayground
gives each {name} of a template a field, marks the blanks, and runs once
every value is in. PromptDiff shows word changes inline, a space parting
a word taken out from the word put in; PromptVersionHistory lists
versions to choose from and restore.

ChartLegend entries that toggle are Tab stops with the focus ring. Each
capture pass starts its page fresh, so dark runs the script from the same
start as light.

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

AGENTS.md

@@ -50,6 +50,7 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - gpui sends a drag's moves to every listener of its type. Each drag payload carries its owner's `EntityId`, and handlers check it.
 - A component that takes a starting value from its owner keeps it in `layout::seeded`: a new value from the owner replaces local drags.
 - The capture harness turns on reduced motion, so shots are still: repeating motion rests on one frame, and a shimmer shows no band.
+- Each capture pass starts its page fresh (`Gallery::fresh`): page state lives under the pass, so the dark pass runs its script from the same start as the light one.
 - The capture harness finds gpui windows by handle through `raw-window-handle`. AppKit popups, which gpui does not own, come from the window list by process and level.
 - Posted events cannot move a macOS window, so window drags are not scripted. `drag_region` follows Zed's title bar.
 - An overlay takes focus with `primitives::take_focus` and returns it with `give_back` on every close path. While open, it takes focus back whenever the focused element leaves the tree (gpui's `on_focus_lost`).