T23b: AI chat, citations

- CitationBadge: a numbered pill after a claim, its source on hover, a press
  opens it; a Tab stop
- SourceCard and SourceList: the sources folded under their count and sites,
  each a card numbered as cited; the fold opens from the keyboard
- SearchProgress: steps waiting, working and done
- WebResultCard and DocumentChunkPreview with matched words washed
- gallery: citation and sources states

examples/gallery/pages/chat/cite.rs

@@ -0,0 +1,123 @@
+use ely_gpui_component::chat::{
+    CitationBadge, DocumentChunkPreview, SearchProgress, Source, SourceList, StepState,
+    WebResultCard,
+};
+use gpui::{App, IntoElement, ParentElement, Styled, Window, div, px};
+
+use crate::{probe::probe, ui::section};
+
+fn sources() -> Vec<Source> {
+    [
+        (
+            "example.com",
+            "Color, in light and dark",
+            "https://example.com/color/light-and-dark",
+            "How one accent reads the same on paper and on charcoal.",
+        ),
+        (
+            "example.org",
+            "Gamma and the eye",
+            "https://example.org/notes/gamma",
+            "Why even steps in gamma space look even to the eye.",
+        ),
+        (
+            "example.net",
+            "Designing dark themes",
+            "https://example.net/dark-themes",
+            "Lift surfaces rather than shade them; depth reads as light.",
+        ),
+    ]
+    .into_iter()
+    .map(|(site, title, url, snippet)| Source {
+        site: site.into(),
+        title: title.into(),
+        url: url.into(),
+        snippet: Some(snippet.into()),
+    })
+    .collect()
+}
+
+pub fn citations(_: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let all = sources();
+    let cite = |ix: usize| {
+        CitationBadge::new(("chat-cite", ix), ix + 1, all[ix].clone())
+            .on_open(move |_, _| log::info!("gallery: open source {ix}"))
+    };
+    section(
+        "CitationBadge / InlineCitation / SourceCard / SourceList / SourcesPanel",
+        "Where an answer's words came from: a numbered pill after the claim, its source a rest of the pointer away; the sources folded under the answer, each a card.",
+        cx,
+    )
+    .child(
+        div()
+            .w(px(560.))
+            .flex()
+            .flex_col()
+            .gap_4()
+            .child(
+                div()
+                    .flex()
+                    .flex_wrap()
+                    .items_center()
+                    .gap_1()
+                    .child("A lift blends a color toward white, in gamma space.")
+                    .child(probe("chat-cite-1", cite(1)))
+                    .child("Dark themes lift further.")
+                    .child(cite(0))
+                    .child(cite(2)),
+            )
+            .child(probe(
+                "chat-sources",
+                div().w(px(560.)).child(
+                    SourceList::new("chat-sources", all.clone())
+                        .on_open(|ix, _, _| log::info!("gallery: open source {ix}")),
+                ),
+            )),
+    )
+}
+
+const PASSAGE: &str = "Accents in dark carry more lift than in light, because a saturated color on charcoal looks louder than the same color on paper.";
+
+pub fn search(_: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let all = sources();
+    let louder = PASSAGE
+        .find("looks louder")
+        .expect("the passage holds its match");
+    let more = PASSAGE
+        .find("more lift")
+        .expect("the passage holds its match");
+    section(
+        "SearchProgress / WebResultCard / DocumentChunkPreview",
+        "A search as it runs, step by step; a result as the web gives it; and a passage found in a document, the words that matched washed.",
+        cx,
+    )
+    .child(
+        div()
+            .w(px(560.))
+            .flex()
+            .flex_col()
+            .gap_4()
+            .child(SearchProgress::new(
+                "chat-search",
+                [
+                    ("Searching for “lift in dark themes”", StepState::Done),
+                    ("Reading 3 sources", StepState::Working),
+                    ("Writing the answer", StepState::Waiting),
+                ],
+            ))
+            .child(
+                WebResultCard::new("chat-result", all[2].clone())
+                    .date("Sep 2026")
+                    .on_open(|_, _| log::info!("gallery: open result")),
+            )
+            .child(
+                DocumentChunkPreview::new(
+                    "lift-notes.pdf",
+                    "Page 1 · Dark is not inverted",
+                    PASSAGE,
+                    vec![more..more + "more lift".len(), louder..louder + "looks louder".len()],
+                )
+                .score(0.86),
+            ),
+    )
+}

examples/gallery/pages/chat/mod.rs

@@ -1,4 +1,5 @@
 mod blocks;
+mod cite;
 mod controls;
 mod talk;
 
@@ -29,6 +30,15 @@ const SCRIPT: &[Step] = &[
     Step::Shot("editing"),
     Step::Key("escape"),
     Step::Wait(200),
+    Step::HoverAt("chat-cite-1", 8.0, 8.0),
+    Step::Wait(700),
+    Step::Shot("citation"),
+    Step::DownAt("chat-sources", 20.0, 10.0),
+    Step::UpAt("chat-sources", 20.0, 10.0),
+    Step::Wait(300),
+    Step::Shot("sources"),
+    Step::DownAt("chat-sources", 20.0, 10.0),
+    Step::UpAt("chat-sources", 20.0, 10.0),
 ];
 
 fn render(window: &mut Window, cx: &mut App) -> AnyElement {
@@ -41,5 +51,7 @@ fn render(window: &mut Window, cx: &mut App) -> AnyElement {
         .child(controls::actions(window, cx))
         .child(controls::status(window, cx))
         .child(controls::thinking(window, cx))
+        .child(cite::citations(window, cx))
+        .child(cite::search(window, cx))
         .into_any_element()
 }