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/0004_reminder_logs.sql

@@ -0,0 +1,11 @@
+-- Add email opt-out flag to clients
+ALTER TABLE "clients" ADD COLUMN "email_opt_out" boolean NOT NULL DEFAULT false;
+
+-- Track sent reminders to prevent duplicate sends
+CREATE TABLE "reminder_logs" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"appointment_id" uuid NOT NULL REFERENCES "appointments"("id") ON DELETE CASCADE,
+	"reminder_type" text NOT NULL,
+	"sent_at" timestamp DEFAULT now() NOT NULL,
+	UNIQUE ("appointment_id", "reminder_type")
+);