Feat: Add collapsible shell

Frontend/src/components/shell/ProjectSelector/ProjectSelector.module.scss

@@ -5,6 +5,10 @@
   --project-drawer-bottom: calc(var(--sidebar-dock-clearance) + var(--project-drawer-gap));
 }
 
+.rootCompact {
+  justify-items: center;
+}
+
 .trigger {
   width: 100%;
   min-width: 0;
@@ -39,6 +43,29 @@
   box-shadow: var(--shadow-soft);
 }
 
+.triggerCompact {
+  width: var(--control-size-xl);
+  min-height: var(--control-size-xl);
+  grid-template-columns: auto;
+  justify-items: center;
+  gap: 0.15rem;
+  padding: var(--space-2) 0;
+  border-radius: var(--radius-xl);
+}
+
+.triggerCompact .triggerLead {
+  width: var(--control-size-md);
+  height: var(--control-size-md);
+}
+
+.triggerCompact .triggerIcon {
+  transform: rotate(0deg);
+}
+
+.triggerCompact .triggerIconOpen {
+  transform: rotate(180deg);
+}
+
 .triggerLead {
   width: var(--control-size-md);
   height: var(--control-size-md);
@@ -99,6 +126,13 @@
   pointer-events: auto;
 }
 
+.rootCompact .scrim,
+.rootCompact .drawer {
+  left: 0;
+  right: auto;
+  width: min(18rem, calc(100vw - 6rem));
+}
+
 .drawer {
   position: absolute;
   inset: calc(var(--project-drawer-top) + var(--project-drawer-gap)) var(--space-4)