refactor(db): switch records layer to Prisma

- Replace hand-written node:sqlite queries with a Prisma client using
  the better-sqlite3 driver adapter
- Version the schema with migrations: baseline table, timestamp
  normalisation, and WAL journal mode
- Store timestamps with an explicit UTC offset so they stop being parsed
  as local time
- Show created/updated times on the edit page, formatted with dayjs
- Move the root redirect into next.config to avoid a prerender error
- Run migrations from the container entrypoint before starting the server

BREAKING CHANGE: DNSMASQ_ADMIN_DB_PATH is replaced by DATABASE_URL, which
must be a Prisma connection URL (file:./data/dnsmasq-admin.db). Existing
database files are migrated in place and need no conversion.

next.config.ts

@@ -2,6 +2,13 @@ import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
   /* config options here */
+  // The root route only ever forwards to /records, so it is handled at the routing layer
+  // instead of by a page component that calls redirect() during render. Rendering first used
+  // to make Next try to validate the redirect target during prerender and report a stray
+  // NEXT_REDIRECT error, even though the 307 itself was served correctly.
+  async redirects() {
+    return [{ source: "/", destination: "/records", permanent: false }]
+  },
   experimental: {
     agentFeedback: true,
   },