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>

scripts/install_into_art_design_pro.py

@@ -137,7 +137,7 @@ def install(root: Path, dry_run: bool = True, verify: bool = False,
             os.replace(temp,route_file)
         finally:
             temp.unlink(missing_ok=True)
-    manifest={'siteforge_version':'8.21.3-dev.1','files':{p.name:_sha(p.read_bytes()) for p in sources}}
+    manifest={'siteforge_version':'8.29.0-dev.1','files':{p.name:_sha(p.read_bytes()) for p in sources}}
     (target/'.siteforge-v819.json').write_text(json.dumps(manifest,indent=2),encoding='utf-8')
     result['installed']=True
     return result