✨ feat: enhance medialib image handling and add asset URL resolution

- Implemented `resolveApiAssetUrl` function to normalize asset URLs based on API base.
- Updated `MedialibImage` component to utilize new asset URL resolution and added support for alt text and class properties.
- Enhanced image loading behavior with improved width measurement and focal point handling.
- Added placeholder image handling and improved accessibility with alt text.
- Introduced new test script for auditing broken links in skill documentation.
- Expanded seeded test content to include medialib entries and updated related tests for pagebuilder previews.
- Improved global setup and teardown logging for clarity on seeded content management.

frontend/src/admin.ts

@@ -1,4 +1,5 @@
 import { mount, unmount, type Component, type SvelteComponent } from "svelte"
+import { apiBaseOverride } from "./lib/store"
 import BlockRenderer from "./blocks/BlockRenderer.svelte"
 
 const previewCssUrl = new URL("./index.css", import.meta.url).toString()
@@ -86,6 +87,11 @@ function createContentBlockDefinition(presentation: BlockPresentation): BlockDef
             position: "relative",
         },
         render(container, row, context) {
+            const previewApiBase = context?.projectBase || context?.apiBase
+            if (previewApiBase) {
+                apiBaseOverride.set(String(previewApiBase))
+            }
+
             const target = document.createElement("div")
             target.dataset.adminPreview = "true"
             container.appendChild(target)
@@ -99,7 +105,12 @@ function createContentBlockDefinition(presentation: BlockPresentation): BlockDef
             })
 
             return {
-                update(nextRow) {
+                update(nextRow, nextContext) {
+                    const nextPreviewApiBase = nextContext?.projectBase || nextContext?.apiBase
+                    if (nextPreviewApiBase) {
+                        apiBaseOverride.set(String(nextPreviewApiBase))
+                    }
+
                     unmount(mountedComponent)
                     target.innerHTML = ""
                     mountedComponent = mount(BlockRenderer as Component<any>, {