swarm-ui: add Dialog/ConfirmDialog sections to the components page

mara (#4172): the components page was out of date against its own
stated rule ("a new primitive gets a section here the same day it's
added"). Dialog and ConfirmDialog are real standalone exported
primitives (AgentsPage uses both directly) with no demo section.

FormField deliberately stays excluded — its own comment already says
it's not a reachable primitive, just TextField/SelectField's shared
internal wrapper, so it was never meant to get one.

Also gave the Table demo's "detail" column a multiselect filter, so
the checkbox popover and reset-filters button — real, daily-used Table
behavior — are actually shown rather than an unfiltered grid.

frontend/packages/swarm-ui/src/pages/ComponentsPage.tsx

@@ -20,6 +20,8 @@ import {
   type SelectOption,
 } from "../ui/select-field/SelectField.js";
 import { Button, type ButtonVariant } from "../ui/button/Button.js";
+import { Dialog } from "../ui/dialog/Dialog.js";
+import { ConfirmDialog } from "../ui/confirm-dialog/ConfirmDialog.js";
 import { Badge, type BadgeTone } from "@hive/shared/badge.js";
 import { GearIcon } from "@hive/shared/icons.js";
 import { Dropdown, type DropdownOption } from "@hive/shared/dropdown.js";
@@ -62,7 +64,17 @@ interface Row {
 
 const TABLE_COLUMNS: TableColumn<Row>[] = [
   { key: "name", header: "name", render: (r) => r.name },
-  { key: "detail", header: "detail", render: (r) => r.detail },
+  {
+    key: "detail",
+    header: "detail",
+    render: (r) => r.detail,
+    // One filterable column, multiselect mode — the checkbox-list popover
+    // + reset-filters button are both real `Table` behavior an operator
+    // hits daily (`AgentsPage`/`HivesPage`), so the demo shows them rather
+    // than a plain unfilterable grid.
+    filterValues: (r) => [r.detail],
+    filterMode: "multiselect",
+  },
   {
     key: "status",
     header: "status",
@@ -181,6 +193,46 @@ function BadgeToggleSample() {
   );
 }
 
+// `Dialog` and `ConfirmDialog` both need `open` state to actually toggle —
+// same "controlled sample needs its own wrapper" reasoning as
+// `TextFieldSample` above.
+function DialogSample() {
+  const [open, setOpen] = useState(false);
+  return (
+    <>
+      <Button onClick={() => setOpen(true)}>open dialog</Button>
+      <Dialog open={open} onClose={() => setOpen(false)} label="sample dialog">
+        <p>
+          Plain content — <code>Dialog</code> supplies the modal wiring (focus
+          trap, Escape, backdrop-click) and the close button; the caller owns
+          everything else, including its own heading if it wants one.
+        </p>
+      </Dialog>
+    </>
+  );
+}
+
+function ConfirmDialogSample() {
+  const [open, setOpen] = useState(false);
+  return (
+    <>
+      <Button onClick={() => setOpen(true)}>open confirm dialog</Button>
+      <ConfirmDialog
+        open={open}
+        label="sample confirm dialog"
+        onCancel={() => setOpen(false)}
+        onConfirm={() => setOpen(false)}
+        confirmLabel="confirm"
+      >
+        <p>
+          The message is caller-owned <code>children</code>, same as{" "}
+          <code>Dialog</code> — only the button row and spacing are shared.
+        </p>
+      </ConfirmDialog>
+    </>
+  );
+}
+
 export function ComponentsPage() {
   return (
     <Panel title="components" icon="🧰">
@@ -278,6 +330,18 @@ export function ComponentsPage() {
         </div>
       </Section>
 
+      <Section title="Dialog">
+        <Sample label="modal, caller-owned content">
+          <DialogSample />
+        </Sample>
+      </Section>
+
+      <Section title="ConfirmDialog">
+        <Sample label="modal, cancel/confirm button row">
+          <ConfirmDialogSample />
+        </Sample>
+      </Section>
+
       <Section title="Badge (@hive/shared — used by swarm-ui and the per-agent page)">
         <div class="components-chip-row">
           {BADGE_TONES.map((tone) => (