Remove legacy-header.css and dead header selectors (#12108)

The old header (div#header, #headerNav, #headerLogo, etc.) was replaced
by .header-bar years ago. No HTML template references these IDs anymore.

- Delete legacy-header.css (168 lines)
- Remove its @import from legacy.css
- Remove dead #header* overrides from page-admin, page-edit, page-plain,
  and page-user CSS entry points

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: cdrini

static/css/legacy-header.css

@@ -19,7 +19,6 @@
  * and imported directly in one of the entry points that are prefixed
  * with `page-` or `js-`
  */
-@import "legacy-header.css";
 @import "legacy-tools.css";
 @import "legacy-wmd.css";
 

static/css/legacy.css

@@ -148,11 +148,6 @@ div.siteSearch.darker {
   background-color: var(--mid-grey);
 }
 /* stylelint-disable selector-max-specificity */
-div#headerNav ul.links li {
-  border-top: 1px solid var(--mid-grey);
-}
-/* stylelint-enable selector-max-specificity */
-/* stylelint-disable selector-max-specificity */
 div#contentHead {
   padding-bottom: 30px;
 }

static/css/page-admin.css

@@ -128,15 +128,12 @@ div#databar a {
 .formElement.pagetype #type\.key {
   width: 100%;
 }
-/* stylelint-disable selector-max-specificity */
 div#revertNotice,
-div#header,
 footer,
 div#bottom,
 .siteSearch {
   display: none;
 }
-/* stylelint-enable selector-max-specificity */
 
 /* Defined in openlibrary/macros/EditButtons.html */
 div.adminDelete {

static/css/page-edit.css

@@ -6,7 +6,6 @@
  * -  https://openlibrary.org/books/OL7521653M/Holes/daisy
  */
 
-div#header,
 footer,
 div#bottom,
 .siteSearch {

static/css/page-plain.css

@@ -43,21 +43,6 @@ body {
   background-color: var(--beige);
 }
 /* stylelint-disable selector-max-specificity */
-div#headerNav {
-  background-color: var(--beige);
-}
-/* stylelint-enable selector-max-specificity */
-/* stylelint-disable selector-max-specificity */
-div#headerNav ul.links li {
-  border-top: 1px solid var(--beige-two);
-}
-/* stylelint-enable selector-max-specificity */
-/* stylelint-disable selector-max-specificity */
-div#headerLogo {
-  background-color: var(--beige);
-}
-/* stylelint-enable selector-max-specificity */
-/* stylelint-disable selector-max-specificity */
 div#background {
   width: 100%;
   background-color: var(--beige);
@@ -88,11 +73,6 @@ div#editHistory {
   display: none;
 }
 /* stylelint-enable selector-max-specificity */
-/* stylelint-disable selector-max-specificity */
-div#headerPlace {
-  background-color: var(--beige);
-}
-
 div#subjectsPage {
   columns: 2;
 }