upgrade: adopt V8.34.1 (multi-image banner carousel + spec-table source modes)

Plain overlay (33 items, same-source lineage, zero patch replay).
Theme suites 35/35; full run 453 passed + 10 known Windows env fails
(suspect-module rerun confirms identical failure set).
Live: container 8.34.1-dev.1; hesupipe home leftover industrial-preset
blocks cleared via studio draft+publish flow — home now renders pure
trade-pro template (sf-section/Chinese blocks = 0).

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

reports/v834/browser-check.json

@@ -0,0 +1,9 @@
+{
+  "cases": 36,
+  "overflows": [],
+  "js_errors": [],
+  "screenshots": [
+    "v834-desktop.png",
+    "v834-phone.png"
+  ]
+}