feat(ui): redesign recent commands display and fix terminal visibility

- Dashboard: add frequency bars for top commands, click-to-copy, time display
- Shell: switch from display:none to visibility:hidden for terminal containers
- CSS: restyle command list with improved hover states and copy indicators

💘 Generated with Crush

Assisted-by: MiniMax-M2.7 via Crush <crush@charm.land>

web/src/components/Shell.jsx

@@ -400,7 +400,7 @@ export default function Shell({ api }) {
 
     const onResize = () => {
       const el = document.getElementById(`terminal-${tabId}`)
-      if (el && el.offsetParent !== null) {
+      if (el && el.style.visibility !== 'hidden' && el.style.position !== 'absolute') {
         fitAddon.fit()
       }
     }
@@ -438,23 +438,25 @@ export default function Shell({ api }) {
     const tryInit = (attempt) => {
       if (cancelled || attempt > 20) return
       const shellCol = document.querySelector('.shell-terminal-col')
-      if (!shellCol || shellCol.offsetParent === null) {
+      if (!shellCol) {
         pending.push(setTimeout(() => tryInit(attempt + 1), 150))
         return
       }
       const container = document.getElementById(`terminal-${tab.id}`)
-      if (!container || container.offsetHeight === 0) {
+      if (!container) {
         pending.push(setTimeout(() => tryInit(attempt + 1), 100))
         return
       }
       if (!tabsRef.current[tab.id]) {
         initTerminal(tab.id, tab)
       }
-      requestAnimationFrame(() => {
-        if (cancelled) return
-        const entry = tabsRef.current[tab.id]
-        if (entry) entry.fitAddon.fit()
-      })
+      if (activeTab === tab.id) {
+        requestAnimationFrame(() => {
+          if (cancelled) return
+          const entry = tabsRef.current[tab.id]
+          if (entry) entry.fitAddon.fit()
+        })
+      }
     }
 
     tryInit(0)
@@ -470,7 +472,7 @@ export default function Shell({ api }) {
         const entry = tabsRef.current[tab.id]
         if (entry) {
           const el = document.getElementById(`terminal-${tab.id}`)
-          if (el && el.offsetParent !== null) {
+          if (el && el.style.visibility !== 'hidden') {
             entry.fitAddon.fit()
           }
         }
@@ -839,7 +841,10 @@ export default function Shell({ api }) {
               key={tab.id}
               id={`terminal-${tab.id}`}
               className="shell-xterm-instance"
-              style={{ display: activeTab === tab.id ? 'block' : 'none' }}
+              style={activeTab === tab.id
+                ? { visibility: 'visible', pointerEvents: 'auto' }
+                : { visibility: 'hidden', pointerEvents: 'none' }
+              }
             />
           ))}
         </div>