chore: migrate to pnpm workspaces monorepo with Turborepo

- Restructure directories: apps/api, apps/admin, apps/website
- Add root pnpm-workspace.yaml, turbo.json, .prettierrc, .gitignore
- Rename packages to @inkreach/api, @inkreach/admin, @inkreach/website
- Add shared packages: packages/tsconfig, packages/shared-types
- Add pnpm.onlyBuiltDependencies for native builds
- Update docs: README.md, structs.md
- All three projects build successfully

apps/api/src/common/decorators/current-user.decorator.ts

@@ -0,0 +1,13 @@
+import { createParamDecorator, ExecutionContext } from '@nestjs/common';
+
+/**
+ * Pulls the authenticated user out of the request, as populated by
+ * the JWT strategy.
+ */
+export const CurrentUser = createParamDecorator(
+  (data: keyof { id: bigint; username: string } | undefined, ctx: ExecutionContext) => {
+    const request = ctx.switchToHttp().getRequest<{ user?: { id: bigint; username: string } }>();
+    const user = request.user;
+    return data ? user?.[data] : user;
+  },
+);