Adopt shared WebUI structural primitives

webui/src/styles/committee.css

@@ -1,39 +1,14 @@
-.committee-page,
-.committee-shell {
+.committee-page {
   height: 100%;
   min-height: 0;
   overflow: hidden;
 }
 
-.committee-shell {
-  display: flex;
-  flex-direction: column;
-  background: var(--surface);
-}
-
-.committee-toolbar {
-  display: flex;
-  align-items: center;
-  gap: 9px;
-  min-height: 58px;
-  padding: 10px 16px;
-  border-bottom: 1px solid var(--border);
-  background: var(--surface-raised);
-}
-
 .committee-search {
-  display: flex;
-  align-items: center;
-  gap: 8px;
-  width: min(460px, 100%);
+  flex: 1 1 460px;
   margin-right: auto;
 }
 
-.committee-search input {
-  min-width: 140px;
-  flex: 1;
-}
-
 .committee-alert {
   margin: 10px 16px 0;
 }
@@ -231,17 +206,6 @@
   gap: 4px !important;
 }
 
-.committee-empty {
-  display: grid;
-  min-height: 180px;
-  place-items: center;
-  color: var(--text-soft);
-}
-
-.committee-empty.compact {
-  min-height: 72px;
-}
-
 .committee-record-dialog {
   width: min(820px, calc(100vw - 32px));
   max-height: min(820px, calc(100vh - 32px));
@@ -292,15 +256,6 @@
 }
 
 @media (max-width: 760px) {
-  .committee-toolbar {
-    align-items: stretch;
-    flex-wrap: wrap;
-  }
-
-  .committee-search {
-    width: 100%;
-  }
-
   .committee-workspace {
     grid-template-columns: minmax(150px, 0.8fr) minmax(0, 1.8fr);
     grid-template-rows: repeat(2, minmax(0, 1fr));