M0: foundation — monorepo, PostGIS schema, deck query, app shell

Greenfield scaffold for Linkder, a swipe-to-hire marketplace for local
professional services.

- pnpm/turbo monorepo: apps/web, packages/{shared,db}
- Postgres 16 + PostGIS via docker compose (ports 5442/6389 to avoid
  clashing with other local stacks)
- Drizzle schema, 23 tables, geography(Point,4326) with GiST indexes
- Domain core in packages/shared: integer-cent money, status transition
  graphs, deck ranking weights, cancellation policy — 46 unit tests
- Deck query: filtering in Postgres on the GiST index, ranking in JS so
  the weights stay tunable — 18 integration tests against a seeded DB
- Deterministic seed placing pros at known distances, including three
  that must NOT appear on a deck (out of radius, unverified, away)
- Next.js 15 app shell with a working swipe deck
- CI: typecheck, lint, test, build against live postgres+redis

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/web/next.config.ts

@@ -0,0 +1,21 @@
+import { config as loadEnv } from 'dotenv';
+import type { NextConfig } from 'next';
+
+// The monorepo keeps one .env at the root; Next only looks in the app directory.
+loadEnv({ path: '../../.env' });
+
+const config: NextConfig = {
+  reactStrictMode: true,
+  // The workspace packages ship TypeScript source, not build output.
+  transpilePackages: ['@linkder/db', '@linkder/shared'],
+  images: {
+    remotePatterns: [
+      { protocol: 'https', hostname: 'picsum.photos' },
+      { protocol: 'https', hostname: '**.r2.dev' },
+    ],
+  },
+  // postgres-js opens raw sockets; it must not be bundled into the server chunk.
+  serverExternalPackages: ['postgres'],
+};
+
+export default config;