Unify builder modes and modularize panels

[a5sh]

Motivation

• Reduce duplication and bloat by consolidating the separate advanced builder into a single unified builder with a simple/advanced mode toggle.
• Improve maintainability by splitting monolithic panel logic into small, focused sub-panel modules that can be reused by both modes.
• Make the advanced layout consistent (left panel list + right panel host) and enable reusing existing panel engines without duplicating UI code.

Description

• Introduce a persistent builder mode toggle component BuilderModeToggle and persist the selected mode in local storage under posterium_builder_mode_v1, replacing the previous header support CTA with a simple/advanced switch.
• Add a small panels registry and types in components/panels/panelTypes.ts and create modular wrappers: SourcePanel, LayersPanel, PosterPanel, BadgesPanel, and SelectionPanel under components/panels/.
• Implement an advanced navigation list AdvancedPanelList and a host/shell BuilderPanelHost that renders the selected panel in the right inspector area in advanced mode.
• Make LayerPanel and Inspector support forced sub-panel rendering and an optional hidden tab bar via new props (forcedPanel, hideTabBar) so advanced mode can reuse them without their internal horizontal tabs.
• Replace the old separate advanced app with a tiny wrapper AdvancedBuilderApp that mounts the main BuilderApp with initialMode="advanced", and update /abuild metadata to boot the unified experience directly in advanced mode.

Testing

• Ran npm run build and a production build completed successfully (astro build / Vite bundle completed).
• Ran npm run typecheck and TypeScript reported existing repository-wide errors unrelated to this change (unused imports and strictness issues in admin/dashboard pieces, some legacy typing gaps such as astro:content), so typecheck did not fully pass in this environment.
• Ran npm test and Vitest exited because there are no test files configured in the repo (no unit tests found).

---

Codex Task

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Workers

The latest updates on your project. Learn more about integrating Git with Workers.

Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	posterium-frontend	ccce007	Commit Preview URL Branch Preview URL	May 08 2026, 06:10 PM