feat(ui): inline-edit dropdowns auto-open + auto-exit on dismiss

When a user clicks an inline-edit affordance for country / timezone /
subdivision, the field flipped to its combobox trigger but the popover
didn't open — they had to click again. And if they dismissed the popover
without picking, the field stayed in edit mode showing a "Select country…"
trigger they couldn't get out of.

Combobox primitives (country / timezone / subdivision) now accept:
  - defaultOpen — open on first render
  - onOpenChange — fired on every open/close transition

InlineCountryField / InlineTimezoneField / and the country + subdivision
fields inside addresses-editor pass defaultOpen=true and use onOpenChange
to auto-exit edit mode when the popover closes without a selection. A
pickedRef gate prevents the close-handler from racing the commit() exit
when the user does pick a value.

Bonus: addresses-editor now renders a flag emoji next to the country name
in the read-only state (regional-indicator pair from the ISO code).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/shared/inline-timezone-field.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useState } from 'react';
+import { useRef, useState } from 'react';
 import { Loader2, Pencil } from 'lucide-react';
 import { toast } from 'sonner';
 
@@ -31,8 +31,12 @@ export function InlineTimezoneField({
 }: InlineTimezoneFieldProps) {
   const [editing, setEditing] = useState(false);
   const [saving, setSaving] = useState(false);
+  // Set true when the user picks a value from the dropdown, so the
+  // popover-close handler knows commit() will exit edit mode itself.
+  const pickedRef = useRef(false);
 
   async function commit(next: string | null) {
+    pickedRef.current = true;
     if (next === (value ?? null)) {
       setEditing(false);
       return;
@@ -56,6 +60,16 @@ export function InlineTimezoneField({
           onChange={(tz) => void commit(tz)}
           countryHint={countryHint ?? undefined}
           data-testid={testId}
+          defaultOpen
+          onOpenChange={(open) => {
+            // Auto-exit edit mode when the dropdown closes without a pick,
+            // so the user isn't stuck looking at the trigger. commit() owns
+            // the exit when a value was selected.
+            if (!open && !pickedRef.current) {
+              setEditing(false);
+            }
+            if (open) pickedRef.current = false;
+          }}
         />
         {saving && <Loader2 className="h-3 w-3 animate-spin text-muted-foreground" />}
       </div>