fix: preserve terminal buffer across tab switches and focus regain

Render all terminal sessions and hide inactive ones with display:none so
xterm instances are no longer unmounted/remounted when switching tabs.

Remove terminal.clear() on the connected status message: the server keeps
the session buffer, and clearing was erasing visible content when the tab
regained focus or reconnected.

- Keep TerminalComponent instances alive in both Desktop and Mobile views.
- Only refit/resize on reconnect instead of clearing.

Closes terminal redraw on focus regain.

apps/web/src/components/features/terminal/DesktopTerminalView.tsx

@@ -172,21 +172,25 @@ export const DesktopTerminalView: React.FC<Props> = ({
       )}
       <div className="terminal-page-content">
         {error && <div className="terminal-error-banner">{error}</div>}
-        {sessions
-          .filter((session) => session.id === activeSessionId)
-          .map((session) => (
-            <div key={session.id} className="terminal-instance active">
-              <TerminalComponent
-                ref={terminalRefs.current[session.id]}
-                instanceId={instanceId}
-                sessionId={session.id}
-                onClose={() => onClose(session.id)}
-                isMobile={false}
-                showControls={!isFullscreen}
-                onTerminalReady={onTerminalReady}
-              />
-            </div>
-          ))}
+        {sessions.map((session) => (
+          <div
+            key={session.id}
+            className={`terminal-instance ${session.id === activeSessionId ? "active" : ""}`}
+            style={{
+              display: session.id === activeSessionId ? "flex" : "none",
+            }}
+          >
+            <TerminalComponent
+              ref={terminalRefs.current[session.id]}
+              instanceId={instanceId}
+              sessionId={session.id}
+              onClose={() => onClose(session.id)}
+              isMobile={false}
+              showControls={!isFullscreen}
+              onTerminalReady={onTerminalReady}
+            />
+          </div>
+        ))}
         {sessions.length === 0 && !loading && (
           <div className="terminal-empty-state">
             <p>No terminal sessions. Press Alt+Shift+N to create one.</p>

apps/web/src/components/features/terminal/MobileTerminalView.tsx

@@ -115,23 +115,27 @@ export const MobileTerminalView: React.FC<Props> = ({
         onClick={onToggleHeader}
       >
         {error && <div className="terminal-error-banner">{error}</div>}
-        {sessions
-          .filter((session) => session.id === activeSessionId)
-          .map((session) => (
-            <div key={session.id} className="terminal-instance active">
-              <TerminalComponent
-                ref={terminalRefs.current[session.id]}
-                instanceId={instanceId}
-                sessionId={session.id}
-                onClose={() => onClose(session.id)}
-                isMobile={true}
-                showControls={false}
-                activeModifier={activeModifier}
-                onModifierChange={onModifierChange}
-                onTerminalReady={onTerminalReady}
-              />
-            </div>
-          ))}
+        {sessions.map((session) => (
+          <div
+            key={session.id}
+            className={`terminal-instance ${session.id === activeSessionId ? "active" : ""}`}
+            style={{
+              display: session.id === activeSessionId ? "flex" : "none",
+            }}
+          >
+            <TerminalComponent
+              ref={terminalRefs.current[session.id]}
+              instanceId={instanceId}
+              sessionId={session.id}
+              onClose={() => onClose(session.id)}
+              isMobile={true}
+              showControls={false}
+              activeModifier={activeModifier}
+              onModifierChange={onModifierChange}
+              onTerminalReady={onTerminalReady}
+            />
+          </div>
+        ))}
         {sessions.length === 0 && !loading && (
           <div className="terminal-empty-state">
             <p>No terminal sessions. Press Alt+Shift+N to create one.</p>

apps/web/src/components/features/terminal/terminal.tsx

@@ -174,9 +174,11 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 							if (msg.status === "connected") {
 								setStatus("connected");
 								setError(null);
-								// Clear terminal and refit after reset/reconnect
+								// Refit after reset/reconnect but do NOT clear the
+								// terminal: the server keeps the session buffer, and
+								// clearing would erase it when the user switches back
+								// to an already-connected session.
 								if (termRef.current) {
-									termRef.current.clear();
 									requestAnimationFrame(() => {
 										if (fitAddonRef.current && termRef.current) {
 											fitAddonRef.current.fit();