fix(ci): use classic JSX + global Preact to fix js.Build resolution

landing-page starter, which uses preact blocks, was only working only in monorepo due to Preact installed in root package.json but not starter package.json.

- Switch js.Build to classic JSX with global factory in `modules/blox-tailwind/layouts/_partials/libraries.html` (JSX=transform, JSXFactory=preact.h, JSXFragment=preact.Fragment)
- Update `modules/blox-tailwind/blox/hero/client.jsx` to call `preact.render` and remove `preact` import
- Remove `preact` import from `modules/blox-tailwind/blox/shared/js/components/Icon.jsx` (classic JSX uses global `preact.h`)
- Keep vendored `assets/dist/lib/preact/preact.min.js` and load it only when `needs_preact` is set
- Fixes CI error “Could not resolve preact/jsx-runtime” without requiring `preact` in each starter

modules/blox-tailwind/blox/hero/client.jsx

@@ -3,7 +3,7 @@
  * Uses the shared component for consistency
  */
 
-import {render} from "preact";
+// Use global preact (loaded via script tag) with classic JSX transform
 import {HeroBlock} from "./component.jsx";
 
 // Render function - immediately renders Hero components
@@ -18,7 +18,7 @@ function renderHeroBlocks() {
         const props = JSON.parse(propsData);
 
         // Render the Preact component into the container
-        render(<HeroBlock {...props} />, block);
+        preact.render(<HeroBlock {...props} />, block);
         console.debug(`✓ Hero block "${block.id}" rendered with Preact`);
       } catch (error) {
         console.error(`Failed to render Hero block "${block.id}":`, error);

modules/blox-tailwind/blox/shared/js/components/Icon.jsx

@@ -1,4 +1,4 @@
-import {h} from "preact";
+// Use classic JSX transform with global preact; no direct import
 
 /**
  * Icon component

modules/blox-tailwind/layouts/_partials/libraries.html

@@ -26,8 +26,9 @@
       {{/* Build the client-side JSX using Hugo's official integration */}}
       {{ $jsx_opts := dict 
         "targetPath" (printf "assets/js/preact-built/%s.js" $block_type)
-        "JSX" "automatic"
-        "JSXImportSource" "preact"
+        "JSX" "transform"
+        "JSXFactory" "preact.h"
+        "JSXFragment" "preact.Fragment"
         "format" "iife"
         "minify" hugo.IsProduction
         "sourceMap" (cond hugo.IsDevelopment "external" "")