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

www/src/content.config.ts

@@ -1,31 +0,0 @@
-import { defineCollection } from 'astro:content';
-import { glob, file } from 'astro/loaders';
-import { z } from 'astro/zod';
-import yaml from 'js-yaml';
-
-const posts = defineCollection({
-  loader: glob({ pattern: '**/*.md', base: './content' }),
-  schema: z.object({
-    title: z.string(),
-    date: z.coerce.date(),
-    updated: z.coerce.date().optional(),
-    category: z.string().optional(),
-    related: z.array(z.string()).optional(),
-  })
-});
-
-const bookmarks = defineCollection({
-  loader: file('./content/bookmarks.yaml', {
-    parser: (text) => {
-      const data = yaml.load(text) as Array<Record<string, unknown>>;
-      return data.map((item, i) => ({ id: String(i), ...item }));
-    },
-  }),
-  schema: z.object({
-    title: z.string(),
-    url: z.string().url(),
-    date: z.coerce.date(),
-  })
-});
-
-export const collections = { posts, bookmarks };