refactor(select): enhance dropdown positioning and implement portal for improved rendering

services/frontend/src/components/primitives/select.tsx

@@ -1,7 +1,14 @@
 "use client";
 
 import { Check, ChevronDown } from "lucide-react";
-import { useEffect, useRef, useState } from "react";
+import {
+  useCallback,
+  useEffect,
+  useLayoutEffect,
+  useRef,
+  useState,
+} from "react";
+import { createPortal } from "react-dom";
 import { cn } from "@/lib/utils";
 
 export interface SelectOption {
@@ -10,6 +17,11 @@ export interface SelectOption {
   hint?: string;
 }
 
+/**
+ * Custom select whose dropdown is portalled to `document.body` so it
+ * never gets clipped by a parent `overflow-y-auto` or `overflow-hidden`.
+ * Position is computed via `getBoundingClientRect()` + fixed positioning.
+ */
 export function Select({
   value,
   onChange,
@@ -26,76 +38,129 @@ export function Select({
   size?: "sm" | "md";
 }) {
   const [open, setOpen] = useState(false);
-  const ref = useRef<HTMLDivElement>(null);
+  const triggerRef = useRef<HTMLButtonElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+  const [pos, setPos] = useState<{ top: number; left: number; width: number }>({
+    top: 0,
+    left: 0,
+    width: 0,
+  });
 
+  // Measure trigger to position the portalled dropdown
+  const measure = useCallback(() => {
+    if (!triggerRef.current) return;
+    const rect = triggerRef.current.getBoundingClientRect();
+    setPos({ top: rect.bottom + 6, left: rect.left, width: rect.width });
+  }, []);
+
+  useLayoutEffect(() => {
+    if (open) measure();
+  }, [open, measure]);
+
+  // Reposition on scroll / resize while open
+  useEffect(() => {
+    if (!open) return;
+    const onReposition = () => measure();
+    window.addEventListener("scroll", onReposition, true);
+    window.addEventListener("resize", onReposition);
+    return () => {
+      window.removeEventListener("scroll", onReposition, true);
+      window.removeEventListener("resize", onReposition);
+    };
+  }, [open, measure]);
+
+  // Close on outside click (covers both trigger and dropdown)
   useEffect(() => {
     if (!open) return;
     const onDoc = (e: MouseEvent) => {
-      if (ref.current && !ref.current.contains(e.target as Node))
-        setOpen(false);
+      const t = e.target as Node;
+      if (triggerRef.current?.contains(t) || dropdownRef.current?.contains(t))
+        return;
+      setOpen(false);
     };
     document.addEventListener("mousedown", onDoc);
     return () => document.removeEventListener("mousedown", onDoc);
   }, [open]);
 
+  // Close on Escape
+  useEffect(() => {
+    if (!open) return;
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === "Escape") setOpen(false);
+    };
+    document.addEventListener("keydown", onKey);
+    return () => document.removeEventListener("keydown", onKey);
+  }, [open]);
+
   const selected = options.find((o) => o.value === value);
 
   return (
-    <div ref={ref} className={cn("relative", className)}>
-      <button
-        type="button"
-        onClick={() => setOpen((o) => !o)}
-        className={cn(
-          "flex w-full items-center justify-between gap-2 rounded-[8px] border border-hairline bg-surface-2 text-left text-ink transition-colors hover:border-signal/40",
-          "focus:outline-none focus:border-signal/60",
-          size === "sm" ? "h-9 px-3 text-xs" : "h-10 px-3.5 text-sm",
-        )}
-      >
-        <span className={cn("truncate", !selected && "text-ink-faint")}>
-          {selected?.label ?? placeholder}
-        </span>
-        <ChevronDown
+    <>
+      <div className={cn("relative", className)}>
+        <button
+          ref={triggerRef}
+          type="button"
+          onClick={() => setOpen((o) => !o)}
           className={cn(
-            "size-4 shrink-0 text-ink-faint transition-transform",
-            open && "rotate-180",
+            "flex w-full items-center justify-between gap-2 rounded-[8px] border border-hairline bg-surface-2 text-left text-ink transition-colors hover:border-signal/40",
+            "focus:outline-none focus:border-signal/60",
+            size === "sm" ? "h-9 px-3 text-xs" : "h-10 px-3.5 text-sm",
           )}
-        />
-      </button>
-
-      {open && (
-        <div
-          className="glass absolute z-50 mt-1.5 max-h-72 w-full overflow-auto p-1.5"
-          style={{ animation: "fade-up 0.14s ease" }}
         >
-          {options.length === 0 && (
-            <div className="px-3 py-2 text-xs text-ink-faint">No options</div>
-          )}
-          {options.map((o) => (
-            <button
-              key={o.value}
-              type="button"
-              onClick={() => {
-                onChange(o.value);
-                setOpen(false);
-              }}
-              className={cn(
-                "flex w-full items-center justify-between gap-2 rounded-[8px] px-3 py-2 text-left text-sm transition-colors",
-                o.value === value
-                  ? "bg-signal/15 text-signal"
-                  : "text-ink hover:bg-surface",
-              )}
-            >
-              <span className="truncate">{o.label}</span>
-              {o.hint && (
-                <span className="mono text-[0.65rem] text-ink-faint">
-                  {o.hint}
-                </span>
-              )}
-              {o.value === value && <Check className="size-3.5 shrink-0" />}
-            </button>
-          ))}
-        </div>
-      )}
-    </div>
+          <span className={cn("truncate", !selected && "text-ink-faint")}>
+            {selected?.label ?? placeholder}
+          </span>
+          <ChevronDown
+            className={cn(
+              "size-4 shrink-0 text-ink-faint transition-transform",
+              open && "rotate-180",
+            )}
+          />
+        </button>
+      </div>
+
+      {open &&
+        createPortal(
+          <div
+            ref={dropdownRef}
+            className="glass fixed z-[9999] max-h-72 overflow-auto p-1.5"
+            style={{
+              top: pos.top,
+              left: pos.left,
+              width: pos.width,
+              animation: "fade-up 0.14s ease",
+            }}
+          >
+            {options.length === 0 && (
+              <div className="px-3 py-2 text-xs text-ink-faint">No options</div>
+            )}
+            {options.map((o) => (
+              <button
+                key={o.value}
+                type="button"
+                onClick={() => {
+                  onChange(o.value);
+                  setOpen(false);
+                }}
+                className={cn(
+                  "flex w-full items-center justify-between gap-2 rounded-[8px] px-3 py-2 text-left text-sm transition-colors",
+                  o.value === value
+                    ? "bg-signal/15 text-signal"
+                    : "text-ink hover:bg-surface",
+                )}
+              >
+                <span className="truncate">{o.label}</span>
+                {o.hint && (
+                  <span className="mono text-[0.65rem] text-ink-faint">
+                    {o.hint}
+                  </span>
+                )}
+                {o.value === value && <Check className="size-3.5 shrink-0" />}
+              </button>
+            ))}
+          </div>,
+          document.body,
+        )}
+    </>
   );
 }