fix(header): restore reference VIP chip geometry and cluster split

The VIP chip never received the reference .but geometry. Commit f03d72c8
narrowed the legacy selector from a descendant to a child combinator as a
side effect of an unrelated user-popover fix, and the contract test then
pinned the narrowed form. Because the VIP anchor lives inside the
hover-show wrapper rather than being a direct child of .navbar-but, it
fell back to the bare .but defaults: 15px type instead of 0.8em, no
0.4em margin, and no padding override.

Restore the descendant selector so both chips share one geometry:

- .navbar-top .navbar-but .but is byte-identical to the reference again,
  giving the VIP chip font-size 0.8em, padding 0.3em 1em !important and
  margin 0.4em
- the publish and VIP anchors are plain inline-block .but elements again
  (the merged flex container no longer blockifies them)
- ml10 is back on the VIP anchor; .navbar-top .navbar-but .but overrides
  it exactly as it does in the reference, so it stays markup parity
  without changing the computed margin

The right cluster was also merged into one .aksrt-navbar-actions flex
container with a 10px gap and zero padding, while the reference emits
three floated .navbar-form.navbar-right groups whose 15px padding is what
produces the inter-cluster spacing. Split them again: publish/VIP in
.navbar-but, theme toggle plus language switcher in a flex ac group, and
the account row in its own group. Measured against the reference, the
publish-to-VIP gap was 19.6px instead of 9.6px, and VIP-to-theme-toggle
was 14.8px instead of 34.8px.

The container rules in header-userbox.css are re-anchored onto the
reference structure: .aksrt-navbar-account owns the only remaining flex
context, .toggle-radius and .aksrt-navbar-language are scoped through
.navbar-form, and the hover-show rule targets .navbar-but. Coverage of
those selectors is unchanged, so the theme toggle, language switcher and
message icon keep their current geometry.

The .aksrt-navbar-actions wrapper and its gap are gone; a negative
assertion now guards against reintroducing them.

Verified: node --test across tests/ (603 passing), php -l on the changed
PHP files, and a stubbed render of aksrt_menu_button() for guest,
logged-in and layout 2.

tests/widget-system/page-display-contract.test.cjs

@@ -142,7 +142,7 @@ test('VIP navigation purchase switches are saved and consumed end to end', () =>
 test('header VIP hover cards match the legacy markup and style contract', () => {
   assert.match(headerMenuButtons, /<span class="hover-show inline-block">/)
   assert.match(headerMenuButtons, /<div class="sub-menu hover-show-con sub-vip-card">/)
-  assert.match(headerMenuButtons, /'<a class="' \. esc_attr\(\$cls\) \. ' but jb-red radius payvip-icon" href="javascript:;">'/)
+  assert.match(headerMenuButtons, /'<a class="' \. esc_attr\(\$cls\) \. ' but jb-red radius payvip-icon ml10" href="javascript:;">'/)
   assert.match(headerMenuButtons, /<svg class="em12 mr3" aria-hidden="true"><use xlink:href="#icon-vip_1"><\/use><\/svg>'/)
   assert.match(headerMenuButtons, /'<a rel="nofollow" class="newadd-btns ' \. esc_attr\(\$class\) \. ' btn-newadd"/)
   assert.equal((headerMenuButtons.match(/Settings::close_sign\(\)/g) || []).length, 2)
@@ -167,7 +167,7 @@ test('header VIP hover cards match the legacy markup and style contract', () =>
   assert.match(legacyMainCss, /\.sub-vip-card \.vip-img\s*\{[^}]*display:\s*none;/s)
   // The hover wrapper must stay a plain block container so the legacy static
   // position of .sub-vip-card matches the reference theme.
-  assert.match(headerCss, /\.navbar-top \.aksrt-navbar-actions > \.hover-show\s*\{[^}]*display:\s*inline-block;/s)
+  assert.match(headerCss, /\.navbar-top \.navbar-but > \.hover-show\s*\{[^}]*display:\s*inline-block;/s)
   assert.doesNotMatch(headerCss, /\.navbar-cta|\.navbar-vip-hover/)
   assert.match(legacyMainCss, /\.navbar-top \.navbar-right \.sub-menu\s*\{[^}]*right:\s*0;/s)
 })
@@ -346,16 +346,21 @@ test('user profile and author widgets render the reference user-card contract',
 })
 
 test('desktop header actions share one row without generic button masks', () => {
-  assert.match(headerNavbar, /aksrt-navbar-actions navbar-form navbar-right/)
+  assert.match(headerNavbar, /navbar-form navbar-right navbar-but/)
+  assert.match(headerNavbar, /navbar-form navbar-right flex ac/)
+  assert.match(headerNavbar, /\$fold \. \$button \. \$right_but/)
   assert.match(headerNavbar, /class="aksrt-nav-icon nav-search-btn main-search-btn"/)
   assert.doesNotMatch(headerNavbar, /class="btn nav-search-btn main-search-btn"/)
-  assert.match(headerCss, /\.navbar-top \.aksrt-navbar-actions\s*\{[^}]*display:\s*flex;[^}]*align-items:\s*center;/s)
+  assert.match(headerCss, /\.navbar-top \.aksrt-navbar-account\s*\{[^}]*display:\s*inline-flex;[^}]*align-items:\s*center;/s)
   assert.match(headerCss, /\.navbar-top \.aksrt-nav-icon,[\s\S]*?background:\s*transparent !important;/)
   // The publish and VIP chips ride the legacy .but geometry verbatim; nothing in
   // the header module may restate their padding, margin, radius or icon size.
-  assert.match(legacyMainCss, /\.navbar-top \.navbar-but > \.but\s*\{[^}]*font-size:\s*0\.8em;[^}]*padding:\s*0\.3em 1em !important;[^}]*margin:\s*0\.4em;/s)
+  // Descendant, not child: the VIP chip lives inside the hover-show wrapper.
+  assert.match(legacyMainCss, /\.navbar-top \.navbar-but \.but\s*\{[^}]*font-size:\s*0\.8em;[^}]*padding:\s*0\.3em 1em !important;[^}]*margin:\s*0\.4em;/s)
   assert.doesNotMatch(headerCss, /\.navbar-cta|\.navbar-vip-hover/)
-  assert.match(headerCss, /\.navbar-top \.aksrt-navbar-actions\s*\{[^}]*gap:\s*10px;/s)
+  // No merged flex container: the three groups keep their own .navbar-form
+  // padding, which is what produces the reference inter-cluster spacing.
+  assert.doesNotMatch(headerCss, /\.aksrt-navbar-actions/)
   assert.match(headerCss, /\.navbar-top \.aksrt-navbar-account > li\s*\{[^}]*position:\s*relative;/s)
   assert.match(headerCss, /\.navbar-top \.aksrt-navbar-account > li > \.sub-menu\s*\{[^}]*top:\s*calc\(100% \+ 5px\);[^}]*right:\s*0;/s)
 })