Create standalone browser port of LTX Athena with authenticated native API transport

frontend/lib/genspace-layout.ts

@@ -0,0 +1,39 @@
+export const GENSPACE_LAYOUT_STORAGE_KEY = 'ltx-genspace-layout'
+
+export const DEFAULT_PROMPT_BAR_HEIGHT = 160
+
+export const PROMPT_BAR_HEIGHT_LIMITS = { min: 140, max: 400 } as const
+
+export type LayoutStorage = Pick<Storage, 'getItem' | 'setItem'>
+
+export function clampPromptBarHeight(height: number): number {
+  return Math.max(
+    PROMPT_BAR_HEIGHT_LIMITS.min,
+    Math.min(PROMPT_BAR_HEIGHT_LIMITS.max, Math.round(height)),
+  )
+}
+
+export function loadPromptBarHeight(storage: LayoutStorage = globalThis.localStorage): number {
+  try {
+    const stored = storage?.getItem(GENSPACE_LAYOUT_STORAGE_KEY)
+    if (!stored) return DEFAULT_PROMPT_BAR_HEIGHT
+    const parsed = JSON.parse(stored) as { promptBarHeight?: unknown }
+    if (typeof parsed.promptBarHeight !== 'number' || !Number.isFinite(parsed.promptBarHeight)) {
+      return DEFAULT_PROMPT_BAR_HEIGHT
+    }
+    return clampPromptBarHeight(parsed.promptBarHeight)
+  } catch {
+    return DEFAULT_PROMPT_BAR_HEIGHT
+  }
+}
+
+export function savePromptBarHeight(height: number, storage: LayoutStorage = globalThis.localStorage): void {
+  try {
+    storage?.setItem(
+      GENSPACE_LAYOUT_STORAGE_KEY,
+      JSON.stringify({ promptBarHeight: clampPromptBarHeight(height) }),
+    )
+  } catch {
+    // Private mode / quota — layout just won't persist.
+  }
+}