fix(locale-switcher): make flag the visual anchor (32x24, no border, no lazy load)

Martin feedback round 3: dropdown still looked 'fuerchterlich' even
with the official flag-icons. Root cause: 14px vertical padding
around an 18px-tall flag meant the flag occupied only 39% of the
trigger height and was dwarfed by whitespace. Plus a 1px black
box-shadow border made flags look 'boxy', and loading='lazy' caused
empty boxes on the four menu flags the moment the <details> opened.

Changes:
- Flag size 24x18 -> 32x24 (+78% area, ~4:3 matches flag-icons)
- Trigger padding 14px 8px -> 6px (flag now 73% of trigger width,
  55% of trigger height, was 46%/39%)
- Drop the artificial 1px black box-shadow outline on flags
- Drop border-radius on flags (real flag-icons look better as
  crisp rectangles)
- Drop object-fit: cover (no longer needed for SVG)
- Drop loading='lazy' and decoding='async' (4 small SVGs, must
  be ready the moment <details> opens, not flash empty boxes)
- min-height: 44px restored on trigger for WCAG 2.5.5 touch target
- Menu border-radius 8 -> 10px, padding tightened, font-size 0.85
  -> 0.9rem for label legibility
- Two-layer box-shadow on menu for subtle elevation

public/css/haus-schleusingen.css

@@ -1476,7 +1476,14 @@ footer {
   }
 }
 
-/* LOCALE SWITCHER — single <details> dropdown, flag-sized trigger */
+/* LOCALE SWITCHER — single <details> dropdown, flag-sized trigger.
+   Design goals (after Martin-feedback round 3):
+     - The flag is the visual anchor of every row, not a tiny icon
+       drowning in padding.
+     - Trigger is a 44×44 touch target with the flag centred, no
+       artificial 1px outline (real flag-icons need no border).
+     - Menu rows are 40px+ tall with comfortable flag+label spacing.
+     - No FOUC on open: SVGs load eager (4 small files). */
 .locale-switcher {
   position: relative;
   display: inline-block;
@@ -1485,15 +1492,14 @@ footer {
 .locale-switcher__trigger {
   display: inline-flex;
   align-items: center;
-  gap: 0.25rem;
-  padding: 14px 8px;
+  gap: 4px;
+  padding: 6px;
+  min-height: 44px;
   border: none;
-  border-radius: 4px;
+  border-radius: 6px;
   background: transparent;
   cursor: pointer;
   list-style: none;
-  min-height: 44px;
-  min-width: 44px;
   color: var(--dark);
   transition:
     background 0.2s,
@@ -1516,11 +1522,10 @@ footer {
 }
 
 .locale-switcher__caret {
-  font-size: 0.65rem;
+  font-size: 0.7rem;
   line-height: 1;
   color: inherit;
   transition: transform 0.2s ease;
-  margin-left: 2px;
 }
 
 .locale-switcher[open] .locale-switcher__caret {
@@ -1533,25 +1538,27 @@ footer {
   right: 0;
   min-width: 180px;
   margin: 0;
-  padding: 0.4rem;
+  padding: 6px;
   list-style: none;
   background: var(--white);
   border: 1px solid var(--warm);
-  border-radius: 8px;
-  box-shadow: 0 8px 24px rgb(0 0 0 / 14%);
+  border-radius: 10px;
+  box-shadow:
+    0 1px 2px rgb(0 0 0 / 6%),
+    0 8px 24px rgb(0 0 0 / 14%);
   z-index: 60;
 }
 
 .locale-switcher__option {
   display: flex;
   align-items: center;
-  gap: 0.6rem;
-  padding: 0.6rem 0.7rem;
-  border-radius: 4px;
+  gap: 10px;
+  padding: 8px 10px;
+  border-radius: 6px;
   text-decoration: none;
   color: var(--dark);
-  font-size: 0.85rem;
-  min-height: 44px;
+  font-size: 0.9rem;
+  font-weight: 500;
 }
 
 .locale-switcher__option.is-current {
@@ -1566,24 +1573,13 @@ footer {
   outline: none;
 }
 
+/* Flag is the visual anchor: 32×24, no border, no rounded corners
+   (flags look better as crisp rectangles than as pills). */
 .locale-switcher .flag {
-  width: 24px;
-  height: 18px;
-  flex: 0 0 24px;
-  border-radius: 2px;
-  box-shadow: 0 0 0 1px rgb(0 0 0 / 15%);
+  width: 32px;
+  height: 24px;
+  flex: 0 0 32px;
   display: block;
-  object-fit: cover;
-}
-
-.locale-switcher__option .flag {
-  width: 24px;
-  height: 18px;
-  flex: 0 0 24px;
-  border-radius: 2px;
-  box-shadow: 0 0 0 1px rgb(0 0 0 / 15%);
-  display: block;
-  object-fit: cover;
 }
 
 .locale-switcher__label {