refactor(assets): vendor 资产迁入标准目录并全仓去除 zibll 标识

- assets/vendor 全量迁移: fontawesome5→assets/fontawesome5, css→assets/css,
  js→assets/js/runtime(避开 14 个同名自有文件), img 合并去重→assets/img,
  fonts→assets/fonts; 删除 assets/vendor
- libs 五个与 widgets/third-party 字节相同的库不重复入库, loader paths 改指向
- 运行时切换: _win.uri=assets 根, loader baseUrl=/js/runtime, enlighter 注入
  路径同步; PHP 7 个引用文件切换并改名 $zibll_*→$runtime_*
- 去品牌: Qinver 头注释/品牌 console.log/演示链接清除, 默认文案中性化
- 功能标识符改名: zib__→aksrt__, zib_ajax→aksrt_ajax, window.zib→
  window.aksrtLegacy, zibllblock/*→aksrtblock/*, .zib-widget→.aksrt-panel,
  .zib-slider→.aksrt-slider, zib_menu_options meta 键等
- 自有 CSS 改名: legacy-utilities/compat-vars/footer shell
- admin SPA 重建; 契约测试同步(路径/断言/文件更名)
- 例外保留: tests/visual 对照环境与 fixtures 前缀(外部 Zibll 产品引用)

验证: php -l 133 个改动文件通过; runtime 86 个 JS node --check 通过;
契约测试 68/70(2 个失败经 stash 对照确认为存量问题)

assets/css/frontend/compat-vars.css

@@ -0,0 +1,98 @@
+/**
+ * legacy Variable Compatibility Layer — Global Bridge
+ *
+ * Maps legacy CSS variable names to AKSRT design tokens.
+ * This file allows existing legacy-style markup and third-party components
+ * that reference legacy variables to work correctly in AKSRT.
+ *
+ * @package AKSRT
+ */
+
+/* ============================================================
+ * Global bridge (all pages)
+ * Maps legacy variables → AKSRT tokens so any legacy-style markup works.
+ * ============================================================ */
+:root {
+  /* Layout (legacy typo preserved for compat) */
+  --mian-max-width: var(--container, 1200px);
+
+  /* Theme color — now matches legacy #f04494 */
+  --theme-color: var(--color-primary, #f04494);
+  --focus-color: var(--color-primary, #f04494);
+  /* legacy focus glow = fixed #fd53a1 @ 0.4 (not the faint primary-soft) */
+  --focus-shadow-color: rgba(253, 83, 161, 0.4);
+
+  /* legacy --focus-color-opacityX — theme-color at fixed alphas.
+     Tracks the runtime theme via --color-primary-rgb (injected by
+     AKSRT_Scripts::inline_css_vars); fallback RGB = #f04494. */
+  --focus-color-opacity1: rgba(var(--color-primary-rgb, 240, 68, 148), 0.1);
+  --focus-color-opacity05: rgba(var(--color-primary-rgb, 240, 68, 148), 0.05);
+  --focus-color-opacity3: rgba(var(--color-primary-rgb, 240, 68, 148), 0.3);
+
+  /* Text hierarchy */
+  --key-color: var(--color-ink);
+  --main-color: var(--color-ink-2);
+  --muted-color: var(--color-ink-3);
+  --muted-2-color: var(--color-ink-4);
+  --muted-3-color: #b1b1b1;
+  --muted-4-color: #d2d2d2;
+
+  /* Surfaces & borders */
+  --body-bg-color: var(--surface-page);
+  --main-bg-color: var(--surface-1);
+  --muted-bg-color: var(--surface-2);
+  --main-border-color: var(--color-line);
+  --muted-border-color: var(--color-line-soft);
+  --main-shadow: rgba(116, 116, 116, 0.08);
+  --main-radius: var(--radius, 8px);
+
+  /* Radius variants */
+  --mini-radius: calc(var(--main-radius) / 1.4);
+
+  /* Blur / glass */
+  --blur-bg: rgba(255, 255, 255, 0.8);
+  --float-btn-bg: rgba(200, 200, 200, 0.4);
+
+  /* Header / footer composites */
+  --header-bg: var(--blur-bg);
+  --header-color: var(--color-ink-2);
+  --footer-bg: var(--surface-1);
+  --footer-color: var(--color-ink-4);
+
+  /* Cards — 对齐 legacy 70% */
+  --posts-card-scale: 70%;
+  --posts-list-scale: 70%;
+  --single-cover-scale: 35%;
+}
+
+/* legacy --this-* context-coloring DEFAULTS live with the .but system in
+ * assets/css/core/buttons.css — they must precede the .b-*/.jb-* color
+ * modifiers in source order for the cascade to resolve colored variants
+ * correctly, so they cannot sit in this later-loaded bridge file.
+ * (Scoped to .but/.badg there, never :root, so .float-btn stays intact.) */
+
+/* ============================================================
+ * Dark mode bridge — 对齐 legacy dark theme
+ * ============================================================ */
+html.dark,
+body.dark-theme {
+  --theme-color: var(--color-primary);
+  --focus-color: var(--color-primary);
+  --focus-shadow-color: rgba(253, 83, 161, 0.25);
+  --key-color: var(--color-ink);
+  --main-color: var(--color-ink-2);
+  --muted-color: var(--color-ink-3);
+  --muted-2-color: var(--color-ink-4);
+  --muted-3-color: #636469;
+  --muted-4-color: #43454a;
+  --body-bg-color: var(--surface-page);
+  --main-bg-color: var(--surface-1);
+  --muted-bg-color: var(--surface-2);
+  --main-border-color: var(--color-line);
+  --muted-border-color: var(--color-line-soft);
+  --main-shadow: rgba(24, 24, 24, 0.1);
+  --blur-bg: rgba(50, 51, 53, 0.8);
+  --float-btn-bg: rgba(70, 70, 70, 0.4);
+  --header-color: var(--color-ink-2);
+  --footer-color: var(--color-ink-4);
+}