perf: LCP-Fix, Banner-Crops, SSR-Cache, Bulk-Windkarte

- TopBanner: JS-Fade-Gate entfernt (opacity-0 bis Hydration schob LCP
  von ~3s auf ~8.6s) — Bild malt jetzt progressiv über den LQIP
- buildBannerResponsive: Breakpoint-Varianten (1/1, 16/9, 24/9) mit
  media-Attributen, quality 60; CMS braucht explizites h neben ar,
  sonst kein Crop (Mobile bekam 1.92:1 unscharf hochskaliert)
- Layout-Preload: ein Link pro Breakpoint-Variante (WebP)
- Layout-Bootstrap-Batch + Logo-SVG-Fetch TTL-gecacht (liefen pro
  SSR-Request); invalidateCollection versteht CSV-Key-Heads
- WindkarteBlock: 40 Einzel-Fetches -> 1 List-Request mit Filter
- app.html: preconnect cms.pm86.de, api.iconify.design, analytics
- u-url Microformat: echte canonicalUrl statt href="#" (SEO-Audit)
- Icon-Subset: 'cloud' ergänzt (kein Runtime-Fetch an iconify mehr)
- StrommixBlock: nutzloses transition-colors entfernt (CLS-Audit)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/routes/[...slug]/+page.server.ts

@@ -6,7 +6,7 @@ import {
   resolveContentImages,
   resolveImageUrls,
 } from '$lib/rusty-image';
-import { buildResponsiveImage, warmResponsiveImage, type ResponsiveImage } from '$lib/rusty-image.server';
+import { buildBannerResponsive, warmResponsiveImage, type ResponsiveImage } from '$lib/rusty-image.server';
 import {
   resolvePostOverviewBlocks,
   resolveSearchableTextBlocks,
@@ -20,9 +20,6 @@ import { env } from '$env/dynamic/public';
 import { error } from '@sveltejs/kit';
 import { sanitizeBlocks } from '$lib/sanitize-blocks.server';
 
-const BANNER_WIDTHS = [640, 960, 1280, 1600, 1920];
-const BANNER_AR = '16/9';
-
 function focalToCss(focal: { x: number; y: number } | undefined): string | null {
   if (!focal) return null;
   return `${(focal.x * 100).toFixed(2)}% ${(focal.y * 100).toFixed(2)}%`;
@@ -106,13 +103,7 @@ export const load: PageServerLoad = async ({ params, locals, fetch, url, setHead
       const primary = extractCmsImageField(imageArr[0]);
       if (primary?.url) {
         topBannerFocalCss = focalToCss(primary.focal);
-        topBannerResponsive = await buildResponsiveImage(primary.url, {
-          widths: BANNER_WIDTHS,
-          fit: 'cover',
-          ar: BANNER_AR,
-          quality: 72,
-          focal: primary.focal,
-        });
+        topBannerResponsive = await buildBannerResponsive(primary.url, primary.focal);
         const socialRel = ensureTransformedImage(primary.url, {
           ...POST_SOCIAL_IMAGE_TRANSFORM,
           focalX: primary.focal?.x,