Move theme menu to the header and group present chrome under it.

Also align Token stats with the settings shell and drop leftover lifecycle toggle wiring.

Co-authored-by: Cursor <cursoragent@cursor.com>

web/theme.js

@@ -0,0 +1,116 @@
+/** Color themes + present chrome — aligned with llm_workflow_engine ThemeToggle. */
+
+export const COLOR_THEMES = [
+  {
+    id: "paper",
+    name: "仿纸暖黄",
+    description: "经典护眼，像 Kindle",
+    icon: "📖",
+  },
+  {
+    id: "modern",
+    name: "现代清爽",
+    description: "干净明快，适合网文",
+    icon: "✨",
+  },
+  {
+    id: "dark",
+    name: "夜间暗色",
+    description: "黑底灰字，夜间必备",
+    icon: "🌙",
+  },
+  {
+    id: "green",
+    name: "豆沙绿",
+    description: "自然疗愈，绿色经典",
+    icon: "🍃",
+  },
+];
+
+/** 呈现壳气质（tone_chrome），与色主题同属「主题」菜单 */
+export const PRESENT_CHROMES = [
+  { id: "default", name: "默认", description: "跟随壳本身" },
+  { id: "messenger", name: "讯息", description: "气泡对话感" },
+  { id: "book", name: "书页", description: "阅读排版感" },
+  { id: "terminal", name: "终端", description: "等宽终端感" },
+];
+
+const STORAGE_KEY = "wa-color-theme";
+const CHROME_STORAGE_KEY = "wa-present-chrome";
+const THEME_IDS = new Set(COLOR_THEMES.map((t) => t.id));
+const CHROME_IDS = new Set(PRESENT_CHROMES.map((t) => t.id));
+const DEFAULT_THEME = "modern";
+const DEFAULT_CHROME = "default";
+
+export function normalizeColorTheme(id) {
+  const v = String(id || "").trim();
+  return THEME_IDS.has(v) ? v : DEFAULT_THEME;
+}
+
+export function getStoredColorTheme() {
+  try {
+    return normalizeColorTheme(localStorage.getItem(STORAGE_KEY));
+  } catch {
+    return DEFAULT_THEME;
+  }
+}
+
+export function themeById(id) {
+  const tid = normalizeColorTheme(id);
+  return COLOR_THEMES.find((t) => t.id === tid) || COLOR_THEMES[1];
+}
+
+export function applyColorTheme(id) {
+  const theme = normalizeColorTheme(id);
+  document.documentElement.setAttribute("data-color-theme", theme);
+  document.documentElement.setAttribute("data-theme", theme);
+  try {
+    localStorage.setItem(STORAGE_KEY, theme);
+  } catch {
+    /* ignore quota / private mode */
+  }
+  return theme;
+}
+
+export function initColorTheme() {
+  return applyColorTheme(getStoredColorTheme());
+}
+
+export function normalizePresentChrome(id) {
+  const v = String(id || "").trim();
+  return CHROME_IDS.has(v) ? v : DEFAULT_CHROME;
+}
+
+export function getStoredPresentChrome() {
+  try {
+    return normalizePresentChrome(localStorage.getItem(CHROME_STORAGE_KEY));
+  } catch {
+    return DEFAULT_CHROME;
+  }
+}
+
+export function chromeById(id) {
+  const cid = normalizePresentChrome(id);
+  return PRESENT_CHROMES.find((t) => t.id === cid) || PRESENT_CHROMES[0];
+}
+
+export function applyPresentChrome(id) {
+  const chrome = normalizePresentChrome(id);
+  document.documentElement.setAttribute("data-present-chrome", chrome);
+  try {
+    localStorage.setItem(CHROME_STORAGE_KEY, chrome);
+  } catch {
+    /* ignore */
+  }
+  document.querySelectorAll(".present-shell").forEach((el) => {
+    for (const cls of [...el.classList]) {
+      if (cls.startsWith("present-tone--")) el.classList.remove(cls);
+    }
+    el.classList.add(`present-tone--${chrome}`);
+  });
+  return chrome;
+}
+
+export function initPresentChrome() {
+  return applyPresentChrome(getStoredPresentChrome());
+}