flatten monorepo, migrate off Vercel

- Remove penfield (split to own repo on Forgejo)
- Move www/ contents to root, rename to wynne.rs
- Swap @astrojs/vercel for @astrojs/node, upgrade to Astro 6
- Remove auth-astro/GitHub OAuth (TinyAuth at proxy layer)
- Remove Vercel deploy webhook
- Switch to local SQLite DB (drop Turso)
- Update generate-stats.js for new build output paths

src/pages/feed.xml.ts

@@ -0,0 +1,33 @@
+import rss from '@astrojs/rss';
+import { getCollection } from 'astro:content';
+import type { APIContext } from 'astro';
+import { getSlug, type Post } from '../lib/posts';
+import { getTxtFiles } from '../lib/txt';
+import { excerpt } from '../lib/format';
+
+export async function GET(context: APIContext) {
+  const posts = await getCollection('posts');
+  const txtFiles = getTxtFiles();
+
+  const items = [
+    ...posts.map(post => ({
+      title: post.data.title,
+      pubDate: post.data.date,
+      link: `/${getSlug(post.id)}`,
+      description: excerpt((post as Post).body) || post.data.title,
+    })),
+    ...txtFiles.map(txt => ({
+      title: txt.name,
+      pubDate: txt.date,
+      link: `/${txt.name}`,
+      description: txt.description || txt.name,
+    })),
+  ].sort((a, b) => b.pubDate.getTime() - a.pubDate.getTime());
+
+  return rss({
+    title: 'wynne.rs',
+    description: 'personal website of lewis m.w.',
+    site: context.site ?? 'https://wynne.rs',
+    items,
+  });
+}