fix: keep conversation composer in the viewport under layout push

Long unbreakable tokens (OAuth URLs) grew the AppFrame center column past the viewport because the layout-push rule used the grid default min-height:auto. Cap --dsh-sidebar-height the same way setBottomHeight does (viewport minus PANEL_MIN) and let the column shrink and wrap.

src/client/Sidebar.tsx

@@ -43,6 +43,7 @@ import {
 import { IconPanelBottomOutline16, IconPanelRightOutline16 } from './icons.tsx'
 import { Workbench, type WorkbenchActions } from './split-pane.tsx'
 import { useNarrowViewport } from './breakpoints.ts'
+import { layoutPushSize } from './layout-push.ts'
 import { parseDesktopEnv } from './desktop-env.ts'
 import { getWcoSnapshot, subscribeWco } from './wco.ts'
 import { getShellPreset } from './shell-presets.ts'
@@ -804,12 +805,15 @@ export function Sidebar(props: { ctx: Context; store: SidebarStore }) {
       dragCommitted.current = true
       stopDragScheduling()
       const last = lastDragSize.current
-      const adoptedWidth = !narrow && state?.panelOpen === true
-        ? Math.min(last?.width ?? state?.width ?? 0, window.innerWidth)
-        : 0
-      const adoptedHeight = !narrow && state?.bottomOpen === true
-        ? Math.min(last?.height ?? state?.bottomHeight ?? 0, window.innerHeight)
-        : 0
+      const { width: adoptedWidth, height: adoptedHeight } = layoutPushSize({
+        narrow,
+        panelOpen: state?.panelOpen === true,
+        bottomOpen: state?.bottomOpen === true,
+        width: last?.width ?? state?.width ?? 0,
+        bottomHeight: last?.height ?? state?.bottomHeight ?? 0,
+        viewportWidth: window.innerWidth,
+        viewportHeight: window.innerHeight,
+      })
       applyDrag(adoptedWidth, adoptedHeight)
       draggingRef.current = false
       measureCenter()
@@ -826,12 +830,15 @@ export function Sidebar(props: { ctx: Context; store: SidebarStore }) {
   // On NARROW viewports the drawer FLOATS over the app shell — no push, the
   // conversation keeps the full width behind the drawer.
   useEffect(() => {
-    const width = !narrow && snapshot.state?.panelOpen === true
-      ? Math.min(snapshot.state.width, window.innerWidth)
-      : 0
-    const height = !narrow && snapshot.state?.bottomOpen === true
-      ? Math.min(snapshot.state.bottomHeight, window.innerHeight)
-      : 0
+    const { width, height } = layoutPushSize({
+      narrow,
+      panelOpen: snapshot.state?.panelOpen === true,
+      bottomOpen: snapshot.state?.bottomOpen === true,
+      width: snapshot.state?.width ?? 0,
+      bottomHeight: snapshot.state?.bottomHeight ?? 0,
+      viewportWidth: window.innerWidth,
+      viewportHeight: window.innerHeight,
+    })
     writeGeometry(width, height)
   }, [narrow, snapshot.state?.panelOpen, snapshot.state?.width, snapshot.state?.bottomOpen, snapshot.state?.bottomHeight])
   // Unmount must release the push (issue #31): when the boundary swaps the

src/client/layout-push.ts

@@ -0,0 +1,32 @@
+/**
+ * Size written to `--dsh-sidebar-width` / `--dsh-sidebar-height`.
+ * The conversation column (output + composer) must keep at least
+ * {@link PANEL_MIN} of the viewport after the bottom panel claims height.
+ */
+import { BOTTOM_MIN, PANEL_MIN } from './state.ts'
+
+export interface LayoutPushInput {
+  narrow: boolean
+  panelOpen: boolean
+  bottomOpen: boolean
+  width: number
+  bottomHeight: number
+  viewportWidth: number
+  viewportHeight: number
+}
+
+export interface LayoutPushSize {
+  width: number
+  height: number
+}
+
+/** Compute the live layout-push size. Narrow drawers float and push 0. */
+export function layoutPushSize(input: LayoutPushInput): LayoutPushSize {
+  if (input.narrow) return { width: 0, height: 0 }
+  const maxWidth = Math.max(PANEL_MIN, input.viewportWidth)
+  const maxHeight = Math.max(BOTTOM_MIN, input.viewportHeight - PANEL_MIN)
+  return {
+    width: input.panelOpen ? Math.min(Math.max(0, input.width), maxWidth) : 0,
+    height: input.bottomOpen ? Math.min(Math.max(0, input.bottomHeight), maxHeight) : 0,
+  }
+}

src/client/layout.css

@@ -44,6 +44,14 @@
 #root [data-dsh-frame] > [data-pane="conversation"],
 #root :has(> [data-slot="conversation"]) {
   margin-bottom: var(--dsh-sidebar-height, 0px);
+  /* Grid/flex items default to min-height:auto. A long unbreakable token
+     (OAuth URL) then grows this column past the viewport and clips the
+     composer + left-rail Settings row. min-height:0 lets the cell shrink;
+     overflow:hidden keeps paint inside the cell; overflow-wrap wraps the
+     token so it cannot force the cell's intrinsic size. */
+  min-height: 0;
+  overflow: hidden;
+  overflow-wrap: anywhere;
   transition: margin-bottom var(--ds-transition-duration-slow) var(--ds-ease-in-out);
 }