tui: add overlay sidebar for narrow screens to improve mobile experience (anomalyco#7288)

Author: thdxr

packages/opencode/src/cli/cmd/tui/routes/session/header.tsx

@@ -99,24 +99,6 @@ export function Header() {
               <Title session={session} />
               <ContextInfo context={context} cost={cost} />
             </box>
-            <Show when={shareEnabled()}>
-              <box flexDirection="row" justifyContent="space-between" gap={1}>
-                <box flexGrow={1} flexShrink={1}>
-                  <Switch>
-                    <Match when={session().share?.url}>
-                      <text fg={theme.textMuted} wrapMode="word">
-                        {session().share!.url}
-                      </text>
-                    </Match>
-                    <Match when={true}>
-                      <text fg={theme.text} wrapMode="word">
-                        /share <span style={{ fg: theme.textMuted }}>copy link</span>
-                      </text>
-                    </Match>
-                  </Switch>
-                </box>
-              </box>
-            </Show>
           </Match>
         </Switch>
       </box>

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -1053,7 +1053,24 @@ export function Session() {
           <Toast />
         </box>
         <Show when={sidebarVisible()}>
-          <Sidebar sessionID={route.sessionID} />
+          <Switch>
+            <Match when={wide()}>
+              <Sidebar sessionID={route.sessionID} />
+            </Match>
+            <Match when={!wide()}>
+              <box
+                position="absolute"
+                top={0}
+                left={0}
+                right={0}
+                bottom={0}
+                alignItems="flex-end"
+                backgroundColor={RGBA.fromInts(0, 0, 0, 70)}
+              >
+                <Sidebar sessionID={route.sessionID} />
+              </box>
+            </Match>
+          </Switch>
         </Show>
       </box>
     </context.Provider>

packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx

@@ -12,7 +12,7 @@ import { useDirectory } from "../../context/directory"
 import { useKV } from "../../context/kv"
 import { TodoItem } from "../../component/todo-item"
 
-export function Sidebar(props: { sessionID: string }) {
+export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
   const sync = useSync()
   const { theme } = useTheme()
   const session = createMemo(() => sync.session.get(props.sessionID)!)
@@ -77,6 +77,7 @@ export function Sidebar(props: { sessionID: string }) {
         paddingBottom={1}
         paddingLeft={2}
         paddingRight={2}
+        position={props.overlay ? "absolute" : "relative"}
       >
         <scrollbox flexGrow={1}>
           <box flexShrink={0} gap={1} paddingRight={1}>