fix(terminal): restore terminal input and cursor visibility

- Fix shell execution to avoid --login flag causing issues on some shells
- Improve terminal initialization timing with requestAnimationFrame
- Force display visibility on xterm instances via CSS
- Ensure container has proper min-height and overflow handling

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

web/src/components/Shell.jsx

@@ -239,15 +239,25 @@ export default function Shell({ api }) {
 
   useEffect(() => {
     const tab = tabs.find(t => t.id === activeTab)
-    if (tab && !tabsRef.current[tab.id]) {
-      const timer = setTimeout(() => initTerminal(tab.id, tab), 50)
-      return () => clearTimeout(timer)
-    } else if (tab && tabsRef.current[tab.id]) {
+    if (!tab) return
+
+    const container = document.getElementById(`terminal-${tab.id}`)
+    if (!container) return
+
+    if (!tabsRef.current[tab.id]) {
       const timer = setTimeout(() => {
-        const { fitAddon } = tabsRef.current[tab.id]
-        fitAddon.fit()
-      }, 50)
+        initTerminal(tab.id, tab)
+        requestAnimationFrame(() => {
+          const entry = tabsRef.current[tab.id]
+          if (entry) entry.fitAddon.fit()
+        })
+      }, 100)
       return () => clearTimeout(timer)
+    } else {
+      requestAnimationFrame(() => {
+        const entry = tabsRef.current[tab.id]
+        if (entry) entry.fitAddon.fit()
+      })
     }
   }, [activeTab, tabs, initTerminal])