Extract groombook/api from monorepo with CI workflow

- Add source code from apps/api
- Add packages/db and packages/types workspace dependencies
- Add GitHub Actions CI workflow (lint, typecheck, test, docker)
- Generate pnpm-lock.yaml
- Add .gitignore

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/db/migrations/0009_client_soft_delete.sql

@@ -0,0 +1,6 @@
+-- Add client status (soft-delete support)
+CREATE TYPE "client_status" AS ENUM ('active', 'disabled');
+
+ALTER TABLE "clients"
+  ADD COLUMN "status" "client_status" NOT NULL DEFAULT 'active',
+  ADD COLUMN "disabled_at" timestamp;