Task 15: product detail anchor tabs + per-product custom sections

User report: product detail page was wrong — section titles are
per-product custom data (CMS wppop_sections migration: Packing &
Delivery / Our Exhibition / Our Certifications / Our Company / FAQ),
not fixed headings; they must drive an anchor tab system like the
CMS [locale]/products/[slug].astro detailTabs.

Data side (both layers, task option 1 + 2):

- theme_pro.product_detail_sections: fields.sections
  [{title, content}] JSON is the structured source; legacy sync
  output that appended sections as trailing body H2 blocks is
  recognized by known/data titles and split out (overview keeps the
  rest; same-title blocks dedupe to the structured version; Features
  body block drops when fields.features renders it)
- sync_cms_data.build_product: store sections/features as structured
  fields JSON, stop appending H2 blocks to the body; stats now count
  entries with a sections field
- Specifications table no longer leaks structural JSON field keys
  (sections/features/specs/gallery/categories) — scalar spec keys
  only

Template side (trade-pro product.html, replaces 12a panel
switching):

- tab sequence is fully data-driven and matches the CMS: Product
  Details (always) -> custom sections (data titles) ->
  Specifications / Features (shown only when data exists)
- tabs are #anchor links, not panel toggles: all sections render
  flat with visible titles (readable and crawlable without JS; native
  anchor jump), JS adds smooth scrolling + scrollspy highlight +
  tab centering in the horizontal scroll row
- section ids are slug-derived (sec-packing-delivery), duplicate
  titles get an index suffix; features grid ports the CMS
  detail-feature-row

Tests: test_trade_pro_product_layout_structure rewritten for the
anchor-tab contract — sections via fields, legacy body-H2 fallback,
spec/features conditional tabs, no-sections product showing only
Product Details + Specifications, spec table free of JSON key leaks,
updated pro.css needles. 30 passed; the 1 failure
(test_trade_pro_blocks_visual_bridge) fails identically on the
previous commit (pre-existing, unrelated).

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

app/theme_pro.py

@@ -8,7 +8,7 @@ import hashlib
 import datetime
 import json
 import re
-from html import escape
+from html import escape, unescape
 from pathlib import Path
 from urllib.parse import quote
 from jinja2 import Environment, FileSystemLoader, select_autoescape
@@ -122,6 +122,95 @@ def media_gallery(page):
         if len(results)>=20:break
     return results
 
+# ── 产品详情自定义区块（CMS wppop_sections 迁移：Packing & Delivery / Our
+#    Exhibition / Our Certifications / Our Company / FAQ——标题来自每产品数据，
+#    不固定）。数据侧两个来源（Task 15）：
+#    1) fields.sections：同步脚本结构化写入的 [{title, content}] JSON；
+#    2) 旧同步产物把区块追加进 body 尾部 <h2> 段——按标题识别拆出为独立区块，
+#    避免正文面板与区块面板重复渲染。正文自有的其他 H2 标题不受影响。──
+KNOWN_SECTION_TITLES=frozenset((
+    'packing & delivery','our exhibition','our certifications','our company','faq','features',
+))
+_H2_RE=re.compile(r'<h2\b[^>]*>([\s\S]*?)</h2>',re.I)
+
+def plain_text(fragment):
+    """HTML 片段 → 单行纯文本（标签剥离 + 实体解码），标题比对用。"""
+    return ' '.join(unescape(re.sub(r'<[^>]+>',' ',fragment or '')).split()).strip()
+
+def parse_pairs(value,keys):
+    """fields 里的 JSON 列表（sections/features）→ [{'title','content'|'desc'}]。
+
+    容忍 JSON 字符串与已解析列表两种形态；缺标题或缺内容的条目丢弃，上限 12 条。
+    """
+    if isinstance(value,str):
+        try:value=json.loads(value)
+        except (TypeError,ValueError):return []
+    if not isinstance(value,list):return []
+    out=[]
+    for item in value:
+        if not isinstance(item,dict):continue
+        title=str(item.get('title') or '').strip()
+        payload=str(item.get(keys[1]) or '').strip()
+        if title and payload:
+            out.append({'title':title,keys[1]:payload})
+    return out[:12]
+
+def split_body_sections(body,wanted):
+    """按 H2 标题把 body 拆为 (overview_html, sections)。
+
+    wanted 为小写标题集合：命中的 H2 与其后到下一个 H2 前的内容拆出为区块；
+    未命中的 H2 与其余内容原样留在 overview（正文自有标题不误拆）。连续命中
+    依次成段；空内容区块不拆（保留原状）。
+    """
+    matches=list(_H2_RE.finditer(body or ''))
+    overview_parts,sections,last=[],[],0
+    for i,m in enumerate(matches):
+        title=plain_text(m.group(1))
+        if title.casefold() not in wanted:continue
+        end=matches[i+1].start() if i+1<len(matches) else len(body or '')
+        content=(body[m.end():end] or '').strip()
+        if not content:continue
+        overview_parts.append(body[last:m.start()])
+        sections.append({'title':title,'content':content})
+        last=end
+    if not sections:return body,[]
+    overview_parts.append(body[last:])
+    return ''.join(overview_parts),sections
+
+def section_ids(sections):
+    """区块锚点 id：sec-<slug(title)>；同名标题追加序号保唯一（sec-faq-1）。"""
+    used={}
+    out=[]
+    for sec in sections:
+        base='sec-'+(slug(sec['title']) or 'section')
+        n=used.get(base,0)
+        used[base]=n+1
+        out.append(base if n==0 else f'{base}-{n}')
+    return out
+
+def product_detail_sections(page,attrs):
+    """产品详情 Tab 区块数据：[(id, title, content HTML)] + features 列表。
+
+    fields.sections（结构化）优先，body H2 识别兜底；两者都有的同名区块只保留
+    结构化版本。Features：fields.features 有数据时 body 里的同名 H2 段拆出丢弃
+    （由结构化数据渲染，防重复）。
+    """
+    structured=parse_pairs(attrs.get('sections'),('title','content'))
+    features=parse_pairs(attrs.get('features'),('title','desc'))
+    covered={s['title'].casefold() for s in structured}
+    if features:covered.add('features')
+    wanted=set(KNOWN_SECTION_TITLES)|covered
+    remainder,body_sections=split_body_sections(str(page.get('body') or ''),wanted)
+    merged=list(structured)
+    for sec in body_sections:
+        if sec['title'].casefold() not in covered:
+            merged.append(sec)
+            covered.add(sec['title'].casefold())
+    merged=merged[:12]
+    return remainder,[
+        {'id':sid,'title':sec['title'],'content':Markup(sanitize(sec['content']))}
+        for sid,sec in zip(section_ids(merged),merged)],features
+
 def select_listing(page,kind,groups,all_records,requested):
     if kind=='category':
         category=text(page,'category') or text(page,'title')
@@ -157,7 +246,11 @@ def make_context(site,page,records,mode='detail',listing_items=None,prepared=Non
     if listing_items is not None and mode=='listing':
         listing=list(listing_items)
     detail_fields=fields(pg)
-    spec=[{'label':str(k).replace('_',' ').capitalize(),'value':str(v)} for k,v in detail_fields.items() if isinstance(v,(str,int,float)) and v not in ('',None) and k not in ('brand','category','model','description','image','cover','url')]
+    # 结构化 JSON/列表字段（同步脚本写入的 sections/features/specs/gallery 等
+    # 附件数据）不进 Specifications 表——表中只列真正的标量规格键。
+    STRUCTURED_FIELD_KEYS=('brand','category','model','description','image','cover','url',
+                           'gallery','sections','features','specs','categories')
+    spec=[{'label':str(k).replace('_',' ').capitalize(),'value':str(v)} for k,v in detail_fields.items() if isinstance(v,(str,int,float)) and v not in ('',None) and k not in STRUCTURED_FIELD_KEYS]
     ownbrand=str(detail_fields.get('brand') or pg.get('title') or '').strip()
     related=[x for x in groups['product']+groups['vehicle'] if str(fields(x).get('brand') or '').casefold()==ownbrand.casefold()] if kind=='brand' else []
     settings=json.loads(site.get('settings_json') or '{}') if isinstance(site.get('settings_json'),str) else site.get('settings_json',{}) or {}
@@ -180,7 +273,15 @@ def make_context(site,page,records,mode='detail',listing_items=None,prepared=Non
     if chrome['nav']:nav=chrome['nav']
     form_endpoint=settings.get('form_endpoint') or ''
     form_endpoint=form_endpoint if isinstance(form_endpoint,str) and form_endpoint.startswith('https://') and not any(x in form_endpoint for x in ('<','>','\"','\n')) else ''
+    # 产品详情自定义区块（Task 15）：fields.sections 结构化优先，body H2 识别
+    # 兜底；overview 为拆出区块后的剩余正文（产品模板专用，content 保持全量
+    # 供其他主题继续整体渲染）。
+    overview_html=pg.get('body') or ''
+    detail_sections=[];detail_features=[]
+    if kind=='product':
+        overview_html,detail_sections,detail_features=product_detail_sections(pg,detail_fields)
     return {'year':datetime.datetime.now(datetime.timezone.utc).year,'theme_color':{'automotive':'#0e1c2c','industrial':'#113f59','corporate':'#f5f6fa','minimal':'#f8f7f3','trade-pro':'#0b3d91'}.get(site.get('theme'),'#ffffff'),'gallery':media_gallery(pg),'form_endpoint':form_endpoint,'site':site,'page':pg,'kind':kind,'records':records,'groups':groups,'listing':listing,
+            'detail_sections':detail_sections,'detail_features':detail_features,'detail_overview':Markup(sanitize(overview_html)),
             'showcase':groups['product'][:6]+groups['vehicle'][:max(0,6-len(groups['product'][:6]))],
             'features':groups['service'][:3], 'stories':groups['post'][:3], 'cases':groups['case'][:3],
             'brands':assets['brands'],'categories':assets['categories'], 'nav':nav,