upgrade: adopt V8.32.0-dev.1 (theme preview iframe fix, editor simple mode)

Overlay 46 upstream items; full patch set re-applied (all patched files
reset by overlay regardless of upstream change status — lesson recorded).
Verified: theme suites 35/35; dual-baseline 418 passed vs pristine
389+29 ours, FAILED-set diff EMPTY (same 10 Windows env fails).
Live: container 8.32.0-dev.1 healthy, hesupipe 192 entries intact,
trade-pro build 203 pages 0 errors.

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

README.md

@@ -1,3 +1,9 @@
+# SiteForge Enterprise V8.32.0-dev.1
+
+本轮修复后台主题预览空白、改进主题图库失败提示，并将可视化编辑器调整为**默认简洁模式**。完整变更、验证与限制见 [README_V8_32.md](README_V8_32.md) 和 [验收报告](reports/v832/V8_32_主题预览与编辑器验收.html)。
+
+---
+
 # SiteForge Enterprise V8.31.0-dev.1
 
 本轮汽车主题按 [Magic Bridge Auto](https://magicbridgeauto.com/) 的导航及选车体验进行行业化重设计，完整说明见 [`README_V8_31.md`](README_V8_31.md)。保留汽车旧主题快照及其他三套主题。