[B2] Rebuild the public website on the qualified v0.44 product surface

[SisyphusZheng]

Part of #1155. Target: v0.44.0-beta.2.

Objective

Use the published beta.1 framework and UI as an external product would: rebuild the official website on exact public candidate artifacts and let the complete documentation/product surface expose integration defects before RC.

Deliverables

• Migrate the website and official Starter to canonical compiled Element and beta.1 UI authoring
• Consume exact npm or packed beta.1 artifacts with no workspace aliases, private source imports or unpublished coupling
• Exercise Content Graph pages, navigation, search, localization, forms, nested UI, SSR/claim and delayed Island delivery
• Publish a beta.2 scorecard covering browser flows, accessibility, output chunks, links, SEO and deployment

Acceptance

• Website and Starter build, test and run from public candidate artifacts alone
• Chromium, Firefox and WebKit pass user-visible critical flows
• Static routes retain zero framework runtime and interactive routes ship only reachable UI/Element behavior
• Generated API/CEM, releases, roadmap, nav, search, locales, SEO and links agree with the beta.2 artifacts
• No framework or UI public-surface change is hidden inside website-local compatibility glue

Blocked by

#1150, #1159, #1176

Authority

• docs/current/VERSION_PLAN.md
• docs/adr/ADR-0143-0-44-compiled-element-model-reentry.md

[SisyphusZheng]

Reconciled into the NEW release train (umbrella #1155, baseline 2936bf0). The old Alpha.1–8 / five-Beta topology is obsolete; supported topology: A10 → B1 → B2 → B3 → RC1 → Stable. This issue is reused (not duplicated) — see the umbrella child-issue checklist for its exact mapping.

Mapped as B2.3 (WWW dogfood/productization): static-first rendering, no mandatory JS where behavior is absent, islands only where needed, real OE UI use, accessibility, SEO, structured data, performance evidence. First paint must not depend on decorative WebGL/client islands (M18). Also covers L8 (route-embedded bilingual content).