feat(blog): static export — output:'export', drop the ISR revalidate exports

The site ships as flat files (out/) served by self-hosted nginx; every
route prerenders at build. next/image ships originals (unoptimized) —
optimization needs a server. The two parvagues revalidate = 60 exports
go with ISR; rebuild-on-push replaces it.

app/parvagues/live/[slug]/page.js

 import { getAllLives, getLiveData, getLivesImages, getLiveTracks } from '@/lib/content';
 import LiveEvent from '@/components/parvagues/LiveEvent';
 
-export const revalidate = 60;
-
 export function generateStaticParams() {
   return getAllLives().map((live) => ({ slug: live.slug }));
 }

app/parvagues/page.js

@@ -7,8 +7,6 @@ import MusicSection from '@/components/parvagues/MusicSection';
 import VideoSection from '@/components/parvagues/VideoSection';
 import BookingForm from '@/components/parvagues/BookingForm';
 
-export const revalidate = 60;
-
 export const metadata = {
   title: { absolute: 'ParVagues - Musique Algorithmique' },
 };

next.config.js

 const path = require('path');
 
 module.exports = {
+  // Static export — the site ships as flat files (out/), served by self-hosted
+  // nginx. Every route is prerendered at build; ISR is replaced by
+  // rebuild-on-push.
+  output: 'export',
+  images: {
+    // `next/image` optimization needs a server; flat files ship originals.
+    unoptimized: true,
+  },
   // Pin the file-tracing root to this project. Without it, Next walks up and
   // finds a stray lockfile in a parent dir (~/package-lock.json) and infers the
-  // wrong workspace root. Also makes standalone output tracing correct for
-  // self-hosting off Vercel later.
+  // wrong workspace root.
   outputFileTracingRoot: __dirname,
   typescript: {
     // Next's build runs its own (stock, non-PnP-aware) TypeScript to type-check