chore: complete @yume → @infiplot rename (post-PR#9)

PR #9 已完成首页和 layout 的视觉品牌迁移，此 commit 补齐剩余的
技术性改名 —— workspace 包名、source import、localStorage 键、
CSS keyframe、内部 header logo、.env.example、README。

- @yume/* → @infiplot/* (6 package.json + 17 imports + lockfile)
- localStorage/sessionStorage: yume:* → infiplot:*
  (含 PR #9 新增的 yume:hintClosed)
- CSS keyframe yume-ripple → infiplot-ripple
- new/play 页面 header logo "云梦" → "InfiPlot"
- 代码注释中的「云梦」style 形容词删除（layout.tsx, page.tsx）
- 根 package.json name + description（描述跟齐 staging
  "AI 实时交互剧情游戏"）
- README: tagline / Vercel deploy URL / 目录树 / engine 描述

保留：prompts.ts 的 LLM 体裁术语「视觉小说/galgame」、CustomForm
placeholder 的「视觉小说画风」（图像模型识别的风格名词）。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/app/play/page.tsx

@@ -24,9 +24,9 @@ import type {
   Session,
   StartResponse,
   VisionResponse,
-} from "@yume/types";
+} from "@infiplot/types";
 
-const MUTED_STORAGE_KEY = "yume:muted";
+const MUTED_STORAGE_KEY = "infiplot:muted";
 
 // Cap how long we wait for the browser to download + decode a scene image
 // before giving up and rendering anyway. Runware's CDN is normally <2s for a
@@ -485,7 +485,7 @@ function PlayInner() {
       const p = PRESETS.find((x) => x.id === presetId);
       if (p) payload = { worldSetting: p.worldSetting, styleGuide: p.styleGuide };
     } else if (params.get("custom") === "1") {
-      const stored = sessionStorage.getItem("yume:custom");
+      const stored = sessionStorage.getItem("infiplot:custom");
       if (stored) {
         try {
           const parsed = JSON.parse(stored) as {
@@ -890,7 +890,7 @@ function PlayInner() {
           className="text-[10px] smallcaps text-clay-600 hover:text-clay-900 transition-colors flex items-center gap-2"
         >
           <i className="fa-solid fa-arrow-left text-[9px]" />
-          云梦
+          InfiPlot
         </Link>
         <div className="flex items-center gap-3 text-[10px] smallcaps text-clay-500 num">
           <span>第 · {String(sceneCount).padStart(3, "0")} · 幕</span>