fix(ui): portal all custom dropdowns to document.body

Custom dropdowns using absolute positioning were clipped by parent
overflow containers (dialogs, scrollable sections). Fixed by rendering
via createPortal with fixed positioning:

- Combobox: default to body portal when no portalContainer prop
- ToolNameSelect: add createPortal + fixed positioning
- AgentSelector: replace overlay+absolute with portal
- ContactInsertSearch: add createPortal + fixed positioning
- ContactSearchBox (instances tab): add createPortal + fixed positioning

ui/web/src/components/chat/agent-selector.tsx

@@ -1,4 +1,5 @@
-import { useState, useEffect } from "react";
+import { useState, useEffect, useRef, useLayoutEffect } from "react";
+import { createPortal } from "react-dom";
 import { useTranslation } from "react-i18next";
 import { Bot, ChevronDown } from "lucide-react";
 import { useHttp } from "@/hooks/use-ws";
@@ -16,6 +17,9 @@ export function AgentSelector({ value, onChange }: AgentSelectorProps) {
   const connected = useAuthStore((s) => s.connected);
   const [agents, setAgents] = useState<AgentData[]>([]);
   const [open, setOpen] = useState(false);
+  const containerRef = useRef<HTMLDivElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+  const [dropdownStyle, setDropdownStyle] = useState<React.CSSProperties>({});
 
   useEffect(() => {
     if (!connected) return;
@@ -28,10 +32,39 @@ export function AgentSelector({ value, onChange }: AgentSelectorProps) {
       .catch(() => {});
   }, [http, connected]);
 
+  // Compute dropdown position for portal rendering
+  useLayoutEffect(() => {
+    if (!open || !containerRef.current) return;
+    const rect = containerRef.current.getBoundingClientRect();
+    setDropdownStyle({
+      position: "fixed",
+      top: rect.bottom + 4,
+      left: rect.left,
+      width: rect.width,
+      zIndex: 9999,
+    });
+  }, [open]);
+
+  // Close on outside click
+  useEffect(() => {
+    if (!open) return;
+    const handler = (e: MouseEvent) => {
+      const target = e.target as Node;
+      if (
+        containerRef.current && !containerRef.current.contains(target) &&
+        (!dropdownRef.current || !dropdownRef.current.contains(target))
+      ) {
+        setOpen(false);
+      }
+    };
+    document.addEventListener("mousedown", handler);
+    return () => document.removeEventListener("mousedown", handler);
+  }, [open]);
+
   const selected = agents.find((a) => a.agent_key === value);
 
   return (
-    <div className="relative">
+    <div ref={containerRef} className="relative">
       <button
         type="button"
         onClick={() => setOpen(!open)}
@@ -44,38 +77,41 @@ export function AgentSelector({ value, onChange }: AgentSelectorProps) {
         <ChevronDown className="h-4 w-4 shrink-0 text-muted-foreground" />
       </button>
 
-      {open && (
-        <>
-          <div className="fixed inset-0 z-40" onClick={() => setOpen(false)} />
-          <div className="absolute left-0 right-0 top-full z-50 mt-1 rounded-lg border bg-popover p-1 shadow-md">
-            {agents.length === 0 && (
-              <div className="px-3 py-2 text-sm text-muted-foreground">
-                {t("noAgentsAvailable")}
-              </div>
-            )}
-            {agents.map((agent) => (
-              <button
-                key={agent.agent_key}
-                type="button"
-                onClick={() => {
-                  onChange(agent.agent_key);
-                  setOpen(false);
-                }}
-                className={`flex w-full items-center gap-2 rounded-md px-3 py-2 text-sm hover:bg-accent ${
-                  agent.agent_key === value ? "bg-accent" : ""
-                }`}
-              >
-                <Bot className="h-4 w-4 shrink-0 text-muted-foreground" />
-                <span className="flex-1 truncate text-left">
-                  {agent.display_name || agent.agent_key}
-                </span>
-                {agent.is_default && (
-                  <span className="text-xs text-muted-foreground">{t("default")}</span>
-                )}
-              </button>
-            ))}
-          </div>
-        </>
+      {open && createPortal(
+        <div
+          ref={dropdownRef}
+          style={dropdownStyle}
+          className="max-h-60 overflow-y-auto rounded-lg border bg-popover p-1 shadow-md"
+        >
+          {agents.length === 0 && (
+            <div className="px-3 py-2 text-sm text-muted-foreground">
+              {t("noAgentsAvailable")}
+            </div>
+          )}
+          {agents.map((agent) => (
+            <button
+              key={agent.agent_key}
+              type="button"
+              onMouseDown={(e) => e.preventDefault()}
+              onClick={() => {
+                onChange(agent.agent_key);
+                setOpen(false);
+              }}
+              className={`flex w-full items-center gap-2 rounded-md px-3 py-2 text-sm hover:bg-accent ${
+                agent.agent_key === value ? "bg-accent" : ""
+              }`}
+            >
+              <Bot className="h-4 w-4 shrink-0 text-muted-foreground" />
+              <span className="flex-1 truncate text-left">
+                {agent.display_name || agent.agent_key}
+              </span>
+              {agent.is_default && (
+                <span className="text-xs text-muted-foreground">{t("default")}</span>
+              )}
+            </button>
+          ))}
+        </div>,
+        document.body,
       )}
     </div>
   );

ui/web/src/components/shared/tool-name-select.tsx

@@ -1,4 +1,5 @@
-import { useMemo, useState, useRef, useEffect } from "react";
+import { useMemo, useState, useRef, useEffect, useLayoutEffect } from "react";
+import { createPortal } from "react-dom";
 import { useTranslation } from "react-i18next";
 import { X, ChevronDownIcon } from "lucide-react";
 import { cn } from "@/lib/utils";
@@ -31,6 +32,8 @@ export function ToolNameSelect({
   const [search, setSearch] = useState("");
   const containerRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLInputElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+  const [dropdownStyle, setDropdownStyle] = useState<React.CSSProperties>({});
 
   const allTools = useMemo<ToolOption[]>(() => {
     const builtin: ToolOption[] = builtinTools.map((t) => ({
@@ -59,11 +62,28 @@ export function ToolNameSelect({
     return { builtin: builtinGroup, custom: customGroup };
   }, [filtered]);
 
+  // Compute dropdown position for portal rendering
+  useLayoutEffect(() => {
+    if (!open || !containerRef.current) return;
+    const rect = containerRef.current.getBoundingClientRect();
+    setDropdownStyle({
+      position: "fixed",
+      top: rect.bottom + 4,
+      left: rect.left,
+      width: rect.width,
+      zIndex: 9999,
+    });
+  }, [open, search]);
+
   // Close on outside click
   useEffect(() => {
     if (!open) return;
     const handler = (e: MouseEvent) => {
-      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+      const target = e.target as Node;
+      if (
+        containerRef.current && !containerRef.current.contains(target) &&
+        (!dropdownRef.current || !dropdownRef.current.contains(target))
+      ) {
         setOpen(false);
       }
     };
@@ -137,8 +157,12 @@ export function ToolNameSelect({
           onClick={() => setOpen(!open)}
         />
       </div>
-      {open && (grouped.builtin.length > 0 || grouped.custom.length > 0) && (
-        <div className="bg-popover text-popover-foreground absolute top-full left-0 z-50 mt-1 max-h-60 w-full overflow-y-auto rounded-md border p-1 shadow-md">
+      {open && (grouped.builtin.length > 0 || grouped.custom.length > 0) && createPortal(
+        <div
+          ref={dropdownRef}
+          style={dropdownStyle}
+          className="bg-popover text-popover-foreground max-h-60 overflow-y-auto rounded-md border p-1 shadow-md"
+        >
           {grouped.builtin.length > 0 && (
             <>
               <div className="text-muted-foreground px-2 py-1 text-[10px] font-semibold uppercase tracking-wider">
@@ -176,7 +200,8 @@ export function ToolNameSelect({
               ))}
             </>
           )}
-        </div>
+        </div>,
+        document.body,
       )}
     </div>
   );

ui/web/src/components/ui/combobox.tsx

@@ -54,21 +54,31 @@ export function Combobox({
     return () => document.removeEventListener("mousedown", handler);
   }, [open]);
 
-  // Compute dropdown position for portal mode
+  // Compute dropdown position — always use fixed positioning for portal rendering
   React.useLayoutEffect(() => {
-    if (!open || !portalContainer?.current || !containerRef.current) return;
+    if (!open || !containerRef.current) return;
     const inputRect = containerRef.current.getBoundingClientRect();
-    const portalRect = portalContainer.current.getBoundingClientRect();
-    const left = inputRect.left - portalRect.left;
-    const maxWidth = portalRect.width - left;
-    setDropdownStyle({
-      position: "absolute",
-      top: inputRect.bottom - portalRect.top + 4,
-      left,
-      width: inputRect.width,
-      maxWidth,
-      zIndex: 50,
-    });
+    if (portalContainer?.current) {
+      const portalRect = portalContainer.current.getBoundingClientRect();
+      const left = inputRect.left - portalRect.left;
+      const maxWidth = portalRect.width - left;
+      setDropdownStyle({
+        position: "absolute",
+        top: inputRect.bottom - portalRect.top + 4,
+        left,
+        width: inputRect.width,
+        maxWidth,
+        zIndex: 50,
+      });
+    } else {
+      setDropdownStyle({
+        position: "fixed",
+        top: inputRect.bottom + 4,
+        left: inputRect.left,
+        width: inputRect.width,
+        zIndex: 9999,
+      });
+    }
   }, [open, search, portalContainer]);
 
   const filtered = React.useMemo(() => {
@@ -98,11 +108,8 @@ export function Combobox({
   const dropdownContent = open && filtered.length > 0 && (
     <div
       ref={dropdownRef}
-      style={portalContainer ? dropdownStyle : undefined}
-      className={cn(
-        "bg-popover text-popover-foreground max-h-60 overflow-y-auto rounded-md border p-1 shadow-md",
-        portalContainer ? "overflow-hidden" : "absolute top-full left-0 z-50 mt-1 min-w-full",
-      )}
+      style={dropdownStyle}
+      className="bg-popover text-popover-foreground max-h-60 overflow-y-auto rounded-md border p-1 shadow-md"
     >
       {filtered.map((o) => (
         <button
@@ -139,9 +146,10 @@ export function Combobox({
           onClick={() => setOpen(!open)}
         />
       )}
-      {portalContainer?.current
-        ? dropdownContent && createPortal(dropdownContent, portalContainer.current)
-        : dropdownContent}
+      {dropdownContent && createPortal(
+        dropdownContent,
+        portalContainer?.current ?? document.body,
+      )}
     </div>
   );
 }

ui/web/src/pages/agents/agent-detail/agent-instances-tab.tsx

@@ -1,4 +1,5 @@
-import { useState, useEffect, useMemo, useRef } from "react";
+import { useState, useEffect, useMemo, useRef, useLayoutEffect } from "react";
+import { createPortal } from "react-dom";
 import { Save, Check, AlertCircle, Users, FileText, Search, UserPlus } from "lucide-react";
 import { useTranslation } from "react-i18next";
 import { Button } from "@/components/ui/button";
@@ -157,15 +158,34 @@ function ContactSearchBox({ existingIDs, onSelect }: { existingIDs: Set<string>;
   const [open, setOpen] = useState(false);
   const { contacts } = useContactSearch(search);
   const containerRef = useRef<HTMLDivElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+  const [dropdownStyle, setDropdownStyle] = useState<React.CSSProperties>({});
 
   // Filter out contacts already in instances
   const filtered = contacts.filter((c) => !existingIDs.has(c.sender_id));
 
+  // Compute dropdown position for portal rendering
+  useLayoutEffect(() => {
+    if (!open || !containerRef.current) return;
+    const rect = containerRef.current.getBoundingClientRect();
+    setDropdownStyle({
+      position: "fixed",
+      top: rect.bottom + 4,
+      left: rect.left,
+      width: rect.width,
+      zIndex: 9999,
+    });
+  }, [open, search]);
+
   // Close on outside click
   useEffect(() => {
     if (!open) return;
     const handler = (e: MouseEvent) => {
-      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+      const target = e.target as Node;
+      if (
+        containerRef.current && !containerRef.current.contains(target) &&
+        (!dropdownRef.current || !dropdownRef.current.contains(target))
+      ) {
         setOpen(false);
       }
     };
@@ -185,8 +205,8 @@ function ContactSearchBox({ existingIDs, onSelect }: { existingIDs: Set<string>;
           className="h-8 w-full rounded-md border bg-transparent pl-7 pr-2 text-xs placeholder:text-muted-foreground focus:outline-none focus:ring-1 focus:ring-ring"
         />
       </div>
-      {open && search.length >= 2 && filtered.length > 0 && (
-        <div className="absolute left-1 right-1 z-50 mt-1 max-h-48 overflow-y-auto rounded-md border bg-popover p-1 shadow-md">
+      {open && search.length >= 2 && filtered.length > 0 && createPortal(
+        <div ref={dropdownRef} style={dropdownStyle} className="max-h-48 overflow-y-auto rounded-md border bg-popover p-1 shadow-md">
           {filtered.map((c) => (
             <button
               key={c.id}
@@ -211,12 +231,14 @@ function ContactSearchBox({ existingIDs, onSelect }: { existingIDs: Set<string>;
               </div>
             </button>
           ))}
-        </div>
+        </div>,
+        document.body,
       )}
-      {open && search.length >= 2 && filtered.length === 0 && contacts.length === 0 && (
-        <div className="absolute left-1 right-1 z-50 mt-1 rounded-md border bg-popover p-3 text-center text-xs text-muted-foreground shadow-md">
+      {open && search.length >= 2 && filtered.length === 0 && contacts.length === 0 && createPortal(
+        <div ref={dropdownRef} style={dropdownStyle} className="rounded-md border bg-popover p-3 text-center text-xs text-muted-foreground shadow-md">
           {t("instances.noContactsFound")}
-        </div>
+        </div>,
+        document.body,
       )}
     </div>
   );

ui/web/src/pages/agents/agent-detail/file-sections/contact-insert-search.tsx

@@ -1,4 +1,5 @@
-import { useState, useEffect, useRef } from "react";
+import { useState, useEffect, useRef, useLayoutEffect } from "react";
+import { createPortal } from "react-dom";
 import { Search, UserPlus } from "lucide-react";
 import { useTranslation } from "react-i18next";
 import { Badge } from "@/components/ui/badge";
@@ -24,12 +25,31 @@ export function ContactInsertSearch({ onInsert }: ContactInsertSearchProps) {
   const [open, setOpen] = useState(false);
   const { contacts } = useContactSearch(search);
   const containerRef = useRef<HTMLDivElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+  const [dropdownStyle, setDropdownStyle] = useState<React.CSSProperties>({});
+
+  // Compute dropdown position for portal rendering
+  useLayoutEffect(() => {
+    if (!open || !containerRef.current) return;
+    const rect = containerRef.current.getBoundingClientRect();
+    setDropdownStyle({
+      position: "fixed",
+      top: rect.bottom + 4,
+      left: rect.left,
+      width: Math.min(rect.width, 384), // max-w-sm = 24rem = 384px
+      zIndex: 9999,
+    });
+  }, [open, search]);
 
   // Close on outside click
   useEffect(() => {
     if (!open) return;
     const handler = (e: MouseEvent) => {
-      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+      const target = e.target as Node;
+      if (
+        containerRef.current && !containerRef.current.contains(target) &&
+        (!dropdownRef.current || !dropdownRef.current.contains(target))
+      ) {
         setOpen(false);
       }
     };
@@ -55,8 +75,8 @@ export function ContactInsertSearch({ onInsert }: ContactInsertSearchProps) {
           className="h-8 w-full max-w-sm rounded-md border bg-transparent pl-7 pr-2 text-xs placeholder:text-muted-foreground focus:outline-none focus:ring-1 focus:ring-ring"
         />
       </div>
-      {open && search.length >= 2 && contacts.length > 0 && (
-        <div className="absolute left-0 z-50 mt-1 max-h-48 w-full max-w-sm overflow-y-auto rounded-md border bg-popover p-1 shadow-md">
+      {open && search.length >= 2 && contacts.length > 0 && createPortal(
+        <div ref={dropdownRef} style={dropdownStyle} className="max-h-48 overflow-y-auto rounded-md border bg-popover p-1 shadow-md">
           {contacts.map((c) => (
             <button
               key={c.id}
@@ -77,12 +97,14 @@ export function ContactInsertSearch({ onInsert }: ContactInsertSearchProps) {
               </div>
             </button>
           ))}
-        </div>
+        </div>,
+        document.body,
       )}
-      {open && search.length >= 2 && contacts.length === 0 && (
-        <div className="absolute left-0 z-50 mt-1 w-full max-w-sm rounded-md border bg-popover p-3 text-center text-xs text-muted-foreground shadow-md">
+      {open && search.length >= 2 && contacts.length === 0 && createPortal(
+        <div ref={dropdownRef} style={dropdownStyle} className="rounded-md border bg-popover p-3 text-center text-xs text-muted-foreground shadow-md">
           {t("instances.noContactsFound")}
-        </div>
+        </div>,
+        document.body,
       )}
     </div>
   );