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

astro.config.mjs

@@ -0,0 +1,23 @@
+import { defineConfig } from 'astro/config';
+import node from '@astrojs/node';
+import db from '@astrojs/db';
+import remarkDirective from 'remark-directive';
+import remarkGfm from 'remark-gfm';
+import remarkSlug from 'remark-slug';
+import remarkSmartypants from 'remark-smartypants';
+import remarkAside from './src/plugins/remark-aside.ts';
+
+export default defineConfig({
+  output: 'static',
+  adapter: node({ mode: 'standalone' }),
+  integrations: [db()],
+  markdown: {
+    remarkPlugins: [
+      remarkGfm,
+      remarkDirective,
+      remarkAside,
+      remarkSlug,
+      remarkSmartypants
+    ]
+  }
+});