add AI-generated landing page photography (Gemini 3 Pro)

20 images generated via gemini-3-pro-image-preview (Nano Banana Pro):
- Documentary street photography style, British-diverse subjects
- 12 square (1:1), 8 landscape (16:9) matching placeholder aspect ratios
- Replaced all ImagePlaceholder components with LandingImage + next/image
- Images in public/images/landing/, served statically

Pages updated: /, /for/charities, /for/fundraisers, /for/volunteers, /for/organisations
New component: LandingImage (next/image with fill + object-cover)

pledge-now-pay-later/src/app/for/organisations/page.tsx

@@ -1,5 +1,5 @@
 import Link from "next/link"
-import { Nav, Footer, BottomCta, ImagePlaceholder } from "../_components"
+import { Nav, Footer, BottomCta, LandingImage } from "../_components"
 
 export default function ForOrganisationsPage() {
   return (
@@ -26,7 +26,7 @@ export default function ForOrganisationsPage() {
               </Link>
             </div>
           </div>
-          <ImagePlaceholder aspect="square" label="Multi-org pledge pipeline — boardroom view" />
+          <LandingImage src="/images/landing/17-orgs-hero-boardroom.jpg" alt="Three people in charity office meeting room discussing pledge pipeline" aspect="square" />
         </div>
       </section>
 
@@ -74,8 +74,8 @@ export default function ForOrganisationsPage() {
             </div>
           </div>
           <div className="space-y-6">
-            <ImagePlaceholder aspect="square" label="Pipeline view — pledges by organisation" />
-            <ImagePlaceholder aspect="video" label="Instalment schedule — multi-month commitment" />
+            <LandingImage src="/images/landing/18-orgs-pipeline.jpg" alt="Laptop showing Kanban-style pledge pipeline view by organisation" aspect="square" />
+            <LandingImage src="/images/landing/19-orgs-instalment-schedule.jpg" alt="Laptop showing instalment schedule with monthly progress bars" aspect="video" />
           </div>
         </div>
       </section>
@@ -83,7 +83,7 @@ export default function ForOrganisationsPage() {
       {/* ── Why this works ── */}
       <section className="py-24 bg-gray-50 px-6">
         <div className="max-w-5xl mx-auto grid md:grid-cols-2 gap-12 items-center">
-          <ImagePlaceholder aspect="square" label="Organisation dashboard — commitment tracking" />
+          <LandingImage src="/images/landing/20-orgs-laptop-desk.jpg" alt="Laptop on charity office desk showing commitment tracking dashboard" aspect="square" />
           <div>
             <h2 className="text-3xl font-black text-gray-900 tracking-tight mb-8">Spreadsheets don&apos;t send reminders</h2>
             <div className="space-y-5">