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>

reports/v829-browser/result.json

@@ -0,0 +1,8 @@
+{
+  "status": "passed",
+  "browser": "Chromium, route-mocked real editor assets",
+  "desktop": "palette/theme/style/undo",
+  "mobile": "390px theme dialog, no horizontal overflow",
+  "page_errors": [],
+  "api_calls": []
+}