swarm-ui: show an agent's details in a popover, not a modal dialog

The details open under the agent badge without dimming or blocking the page; a click outside or Escape closes it. New ui/popover primitive (anchored, portal, no backdrop) with a sample on the components page. A confirm or link dialog opened from inside it stays modal, and the popover ignores clicks and Escape that belong to that dialog. AgentDetailDialog becomes AgentDetailPopover.

frontend/packages/swarm-ui/src/pages/agents/AgentTerminalPage.tsx

@@ -9,10 +9,10 @@
 // plain page reload should all re-open the tab instead of landing on a
 // page with no way back into the tab row. `useDynamicTabs().open()` is
 // idempotent (dedupes by href), so this is safe to call every mount.
-import { useEffect, useState } from "preact/hooks";
+import { useEffect, useRef, useState } from "preact/hooks";
 import type { RouteComponentProps } from "wouter-preact";
 import { Badge } from "@hive/shared/badge.js";
-import { AgentDetailDialog } from "../../agent/detail/AgentDetailDialog.js";
+import { AgentDetailPopover } from "../../agent/detail/AgentDetailPopover.js";
 import { AgentIcon } from "../../agent/AgentIcon.js";
 import {
   AgentTermPreview,
@@ -48,10 +48,12 @@ export function AgentTerminalPage({
     // instead of once per terminal `page`.
   }, [page]);
 
-  // The agent's details open in a dialog over the terminal, so reading or
-  // changing them never means leaving it. A subagent's terminal opens its
-  // agent's details: a subagent has none of its own.
+  // The agent's details open in a popover under its badge, so reading or
+  // changing them never means leaving the terminal, or dimming it. A
+  // subagent's terminal opens its agent's details: a subagent has none of its
+  // own.
   const [detailOpen, setDetailOpen] = useState(false);
+  const badgeRef = useRef<HTMLSpanElement>(null);
 
   return (
     <div class="ui-agent-terminal-page">
@@ -61,18 +63,22 @@ export function AgentTerminalPage({
         fullHeight
         showHeaderBadges
         leading={
-          <Badge
-            icon={<AgentIcon name={name} small />}
-            value={name}
-            title={`open ${name}'s details`}
-            onClick={() => setDetailOpen(true)}
-          />
+          <span ref={badgeRef}>
+            <Badge
+              icon={<AgentIcon name={name} small />}
+              value={name}
+              title={`${detailOpen ? "close" : "open"} ${name}'s details`}
+              expanded={detailOpen}
+              onClick={() => setDetailOpen((o) => !o)}
+            />
+          </span>
         }
       />
-      <AgentDetailDialog
+      <AgentDetailPopover
         agent={name}
         open={detailOpen}
         onClose={() => setDetailOpen(false)}
+        anchorRef={badgeRef}
       />
     </div>
   );