chore: import SiteForge Factory V5 source (baseline)

导入 SiteForge Factory V5 基线源码：
- FastAPI + SQLite + Docker Compose（Web + Worker）架构
- 四套商业主题 × 14 页面模板（1.1.0，含历史版本快照）
- 四种建站模式骨架 + 迁移审计 + 发布门禁
- 52 项 pytest 测试
- 补全计划主文档 docs/superpowers/plans/

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

app/responsive.py

@@ -0,0 +1,25 @@
+"""Safe per-device block CSS using validated data-block identifiers."""
+import re,json
+
+def editor_css(blocks):
+    tablet=[];mobile=[]
+    for b in blocks:
+        uid=b.get('id','')
+        if not re.fullmatch('[a-zA-Z0-9_-]{4,50}',uid):continue
+        s=b.get('style') or {}
+        try:
+            tp=min(120,max(0,int(s.get('tablet_padding',50))))
+            mp=min(120,max(0,int(s.get('mobile_padding',28))))
+        except (TypeError,ValueError):tp,mp=50,28
+        tablet.append(f'.sf-section[data-block="{uid}"]{{--sf-pad:{tp}px}}')
+        mobile.append(f'.sf-section[data-block="{uid}"]{{--sf-pad:{mp}px}}')
+        if s.get('hide_tablet') is True:tablet.append(f'.sf-section[data-block="{uid}"]{{display:none}}')
+        if s.get('hide_mobile') is True:mobile.append(f'.sf-section[data-block="{uid}"]{{display:none}}')
+    return '@media(max-width:820px){'+''.join(tablet)+'}@media(max-width:540px){'+''.join(mobile)+'}'
+
+def site_css(entries):
+    items=[]
+    for entry in entries:
+        meta=json.loads(entry.get('meta_json') or '{}')
+        items.extend(meta.get('blocks',[]) if isinstance(meta.get('blocks'),list) else [])
+    return editor_css(items)