system: simplify mobile overview

This removes the redundant icons at the top of the overview

resources/browserhtml/system/mobile_overview.css

···
   gap: var(--spacing-sm);
 }
 
-.header-button {
-  background: var(--bg-menu);
-  border: none;
-  color: var(--color-text-menu);
-  width: 40px;
-  height: 40px;
-  border-radius: 50%;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  cursor: pointer;
-  transition: background 0.2s ease;
-}
-
-.header-button:hover {
-  background: var(--color-menu-item-hover);
-}
-
 .grid {
   flex: 1;
   overflow-y: auto;

resources/browserhtml/system/mobile_overview.js

···
       new CustomEvent("tab-select", {
         bubbles: true,
         detail: { tabId: tab.id },
-      })
+      }),
     );
     this.close();
   }
···
         new CustomEvent("tab-close", {
           bubbles: true,
           detail: { tabId: tab.id },
-        })
+        }),
       );
     }, 300);
   }
···
 
   handleHome() {
     this.dispatchEvent(new CustomEvent("tab-home", { bubbles: true }));
-    this.close();
-  }
-
-  handleDone() {
     this.close();
   }
 
···
           new CustomEvent("tab-close", {
             bubbles: true,
             detail: { tabId: tab.id },
-          })
+          }),
         );
       }, 300);
     } else {
···
       <div class="container">
         <div class="header">
           <span class="header-title">${tabText}</span>
-          <div class="header-actions">
-            <button class="header-button" @click=${this.handleHome}>
-              <lucide-icon name="house"></lucide-icon>
-            </button>
-            <button class="header-button" @click=${this.handleDone}>
-              <lucide-icon name="check"></lucide-icon>
-            </button>
-          </div>
         </div>
 
         <div class="grid">
···
                   <lucide-icon name="x"></lucide-icon>
                 </button>
               </div>
-            `
+            `,
           )}
 
           <div class="home-card" @click=${this.handleHome}>