feat: integrate dashboard modules and document history

frontend/public/styles.css

@@ -180,12 +180,35 @@ body {
   backdrop-filter: blur(12px);
 }
 
+.header-left,
+.header-right,
 .brand-block,
 .header-actions {
   position: relative;
   z-index: 2;
 }
 
+.header-left {
+  display: flex;
+  align-items: center;
+  gap: 18px;
+  flex: 0 0 auto;
+  min-width: 0;
+}
+
+.header-right {
+  margin-left: auto;
+  display: flex;
+  align-items: center;
+  gap: 18px;
+  min-width: 0;
+}
+
+.brand-block {
+  flex: 0 0 auto;
+  width: 180px;
+}
+
 .dashboard-header .eyebrow {
   color: var(--color-accent);
   margin-bottom: 2px;
@@ -199,14 +222,13 @@ body {
 }
 
 .header-center {
-  margin-left: auto;
-  margin-right: 48px;
   display: inline-flex;
-  justify-content: center;
+  justify-content: flex-end;
   gap: 24px;
   flex-wrap: nowrap;
   white-space: nowrap;
   z-index: 1;
+  flex: 0 0 auto;
 }
 
 .nav-pill {
@@ -246,6 +268,48 @@ body {
   align-items: center;
   gap: 6px;
   position: relative;
+  padding-left: 18px;
+  border-left: 1px solid #dbe2ea;
+}
+
+.header-date-controls {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  margin-left: 0;
+  flex: 0 0 auto;
+  min-width: 0;
+}
+
+.header-date-label {
+  font-size: 12px;
+  font-weight: 800;
+  color: #64748b;
+}
+
+.header-date-field {
+  display: inline-flex;
+  align-items: center;
+  min-height: 36px;
+  padding: 0 10px;
+  border: 1px solid #dbe2ea;
+  border-radius: 999px;
+  background: #fff;
+}
+
+.header-date-field input {
+  border: 0;
+  background: transparent;
+  color: var(--color-text);
+  font-size: 12px;
+  font-weight: 700;
+  outline: none;
+}
+
+.header-date-sep {
+  color: #94a3b8;
+  font-size: 12px;
+  font-weight: 800;
 }
 
 .ghost-button {
@@ -1139,18 +1203,37 @@ body {
     justify-content: space-between;
   }
 
+  .header-left,
+  .header-right {
+    width: 100%;
+  }
+
+  .header-right {
+    justify-content: space-between;
+  }
+
   .header-center {
     position: static;
     transform: none;
-    order: 3;
-    width: 100%;
-    justify-content: flex-start;
+    order: 2;
+    width: auto;
+    justify-content: flex-end;
     margin-top: 8px;
     overflow-x: auto;
   }
 
   .header-actions {
     flex-wrap: wrap;
+    padding-left: 0;
+    border-left: 0;
+  }
+
+  .header-date-controls {
+    order: 2;
+    width: auto;
+    justify-content: flex-start;
+    margin-left: 0;
+    margin-top: 8px;
   }
 
   .seatmap-content {