upgrade: adopt V8.31.1 (theme 1.3/1.4 redesigns, editor deep-canvas, guided launch, component library)

Overlay 190 upstream items (V8.22→8.31) preserving trade-pro theme,
registry tests, and design docs. Re-applied full patch set on identical
anchors (discovery/env_for/blocks.css/type-mapping/locale-override/
theme_color/frontend entries/test_theme_pro_v3 mods) plus compose pins.

Verified: theme suites 35/35; dual-baseline full run 415 passed vs
pristine 386+29 ours, FAILED-set diff EMPTY (same 10 Windows env fails).
Live: container 8.31.1-dev.1 healthy, hesupipe 192 entries intact,
trade-pro build 203 pages 0 errors.

Co-Authored-By: Claude Code <noreply@anthropic.com>

themes/automotive/pages/brand.html

@@ -1 +1,3 @@
-<section class="pro-inner-hero pro-brand-hero"><div class="pro-wrap pro-brand-hero-grid"><div><span class="pro-eyebrow">BRAND PROFILE / PARTNERS</span><h1>{{page.title}}</h1><p>{{page.summary}}</p></div><div class="pro-brand-media">{{cover(page,'brand')}}</div></div></section><section class="pro-section"><div class="pro-wrap">{{body_copy(content,page)}}{% if related %}{{section_title('PRODUCT LINE','相关产品','/products/')}}{{grid(related,'product')}}{% endif %}</div></section>
+<div class="auto31-brand pro-v30-page"><section class="auto31-page-banner auto31-brand-banner"><div class="pro-wrap auto31-brand-intro"><div><nav class="auto31-crumb"><a href="/">首页</a> / <a href="/brands/">品牌中心</a> / <span>{{page.title}}</span></nav><span class="pro-eyebrow">BRANDS / COLLECTION</span><h1>{{page.title}}</h1><p>{{page.summary or '浏览该品牌的介绍与相关车型。'}}</p><a href="#auto31-brand-models" class="auto31-primary">{{auto_icon("car")}} 查看品牌车型</a></div>{% if page.cover %}<div class="auto31-brand-photo"><img src="{{safe_image(page.cover)}}" alt="{{page.title}}" loading="eager" decoding="async" fetchpriority="high"></div>{% endif %}</div></section>
+<section id="auto31-brand-models" class="pro-section auto31-brand-products"><div class="pro-wrap"><div class="auto31-section-heading"><div><span class="pro-eyebrow">MODEL LINEUP</span><h2>{{page.title}} · 相关车型</h2></div><a href="/products/">{{auto_icon("grid")}} 全部车型</a></div>{{grid(related,'vehicle',true)}}</div></section>
+<section class="pro-section auto31-brand-story"><div class="pro-wrap auto31-story-grid"><div><span class="pro-eyebrow">BRAND PROFILE</span><h2>关于 {{page.title}}</h2></div><div>{{body_copy(content,page)}}</div></div></section></div>