Improve readability and randomize guest landing pet.

Pair Share Tech Mono body text with Press Start 2P display accents, and show a randomized dressed pixel character for signed-out homepage previews.

lib/landing-random-pet.ts

@@ -0,0 +1,117 @@
+import {
+  DEFAULT_AVATAR_NAME,
+  type AvatarCustomization,
+} from "@/lib/avatar-customization-storage";
+import {
+  CHARACTER_LAYERS,
+  COLOR_PRESETS,
+  NONE_VARIANT_ID,
+  type CharacterLayerId,
+} from "@/lib/character/presets";
+import { ROOM_BACKGROUNDS } from "@/lib/room-backgrounds";
+
+const GUEST_PET_STORAGE_KEY = "habit-pet-guest-landing-pet";
+
+const SKIN_TONE_IDS = [
+  "porcelain",
+  "fair",
+  "light",
+  "medium",
+  "tan",
+  "brown",
+  "dark",
+  "deep",
+  "onyx",
+] as const;
+
+const OUTFIT_COLOR_IDS = [
+  "red",
+  "orange",
+  "yellow",
+  "green",
+  "blue",
+  "indigo",
+  "black",
+  "white",
+] as const;
+
+const EYE_COLOR_IDS = ["blue", "black", "green", "brown"] as const;
+
+const HAIR_COLOR_IDS = ["brown", "black", "yellow", "red", "orange", "white"] as const;
+
+function pickRandom<T>(items: readonly T[]): T {
+  return items[Math.floor(Math.random() * items.length)]!;
+}
+
+function presetHsl(id: string) {
+  const preset = COLOR_PRESETS.find((entry) => entry.id === id);
+  if (!preset) {
+    throw new Error(`Missing color preset: ${id}`);
+  }
+
+  return { ...preset.hsl };
+}
+
+function pickRandomVariant(
+  layerId: Exclude<CharacterLayerId, "skin">,
+  allowNone = false,
+): string {
+  const layer = CHARACTER_LAYERS.find((entry) => entry.id === layerId);
+  if (!layer) {
+    throw new Error(`Missing character layer: ${layerId}`);
+  }
+
+  const options = layer.variants
+    .map((variant) => variant.id)
+    .filter((id) => allowNone || id !== NONE_VARIANT_ID);
+
+  return pickRandom(options);
+}
+
+export function buildRandomLandingPetCustomization(): AvatarCustomization {
+  const freeRooms = ROOM_BACKGROUNDS.filter((room) => room.free).map(
+    (room) => room.id,
+  );
+
+  return {
+    name: DEFAULT_AVATAR_NAME,
+    colors: {
+      skin: presetHsl(pickRandom(SKIN_TONE_IDS)),
+      pants: presetHsl(pickRandom(OUTFIT_COLOR_IDS)),
+      shoes: presetHsl(pickRandom(OUTFIT_COLOR_IDS)),
+      torso: presetHsl(pickRandom(OUTFIT_COLOR_IDS)),
+      eyes: presetHsl(pickRandom(EYE_COLOR_IDS)),
+      head: presetHsl(pickRandom(HAIR_COLOR_IDS)),
+    },
+    variants: {
+      skin: "skin-1",
+      pants: pickRandomVariant("pants"),
+      shoes: pickRandomVariant("shoes"),
+      torso: pickRandomVariant("torso"),
+      eyes: pickRandomVariant("eyes"),
+      head: pickRandomVariant("head", Math.random() < 0.15),
+    },
+    customized: true,
+    equippedItems: [],
+    roomBackground: pickRandom(freeRooms),
+  };
+}
+
+export function getGuestLandingPetCustomization(): AvatarCustomization {
+  if (typeof window === "undefined") {
+    return buildRandomLandingPetCustomization();
+  }
+
+  try {
+    const cached = sessionStorage.getItem(GUEST_PET_STORAGE_KEY);
+    if (cached) {
+      return JSON.parse(cached) as AvatarCustomization;
+    }
+
+    const next = buildRandomLandingPetCustomization();
+    sessionStorage.setItem(GUEST_PET_STORAGE_KEY, JSON.stringify(next));
+    return next;
+  } catch {
+    return buildRandomLandingPetCustomization();
+  }
+}