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/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "lib": ["DOM", "DOM.Iterable", "ES2022"],
+    "jsx": "preserve",
+    "noEmit": true,
+    "allowJs": true,
+    "incremental": true,
+    "plugins": [{ "name": "next" }],
+    "paths": { "@/*": ["./src/*"] }
+  },
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
+  "exclude": ["node_modules"]
+}