feat(orders): issued_orders schema + migration

Pre-existing quotations.project_code + ai_chat_messages FK drift is captured in its own reconcile_quotations_aichat_fk migration; the issued_orders migration is purely additive.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

prisma/migrations/20260609085127_reconcile_quotations_aichat_fk/migration.sql

@@ -0,0 +1,8 @@
+-- DropForeignKey
+ALTER TABLE `ai_chat_messages` DROP FOREIGN KEY `fk_ai_chat_conv`;
+
+-- AlterTable
+ALTER TABLE `quotations` MODIFY `project_code` VARCHAR(100) NULL;
+
+-- AddForeignKey
+ALTER TABLE `ai_chat_messages` ADD CONSTRAINT `ai_chat_messages_conversation_id_fkey` FOREIGN KEY (`conversation_id`) REFERENCES `ai_conversations`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

prisma/migrations/20260609085152_issued_orders/migration.sql

@@ -0,0 +1,52 @@
+-- AlterTable
+ALTER TABLE `company_settings` ADD COLUMN `issued_order_number_pattern` VARCHAR(100) NULL,
+    ADD COLUMN `issued_order_type_code` VARCHAR(10) NULL;
+
+-- CreateTable
+CREATE TABLE `issued_orders` (
+    `id` INTEGER NOT NULL AUTO_INCREMENT,
+    `po_number` VARCHAR(50) NULL,
+    `customer_id` INTEGER NULL,
+    `status` ENUM('draft', 'sent', 'confirmed', 'completed', 'cancelled') NOT NULL DEFAULT 'draft',
+    `currency` VARCHAR(10) NULL DEFAULT 'CZK',
+    `vat_rate` DECIMAL(5, 2) NULL DEFAULT 21.00,
+    `apply_vat` BOOLEAN NULL DEFAULT true,
+    `exchange_rate` DECIMAL(10, 4) NULL DEFAULT 1.0000,
+    `order_date` DATE NULL,
+    `delivery_date` DATE NULL,
+    `language` VARCHAR(5) NULL DEFAULT 'cs',
+    `delivery_terms` VARCHAR(500) NULL,
+    `payment_terms` VARCHAR(500) NULL,
+    `issued_by` VARCHAR(255) NULL,
+    `notes` TEXT NULL,
+    `internal_notes` TEXT NULL,
+    `created_at` DATETIME(0) NULL DEFAULT CURRENT_TIMESTAMP(0),
+    `modified_at` DATETIME(0) NULL,
+
+    UNIQUE INDEX `idx_issued_orders_number_unique`(`po_number`),
+    INDEX `issued_orders_customer_id`(`customer_id`),
+    INDEX `idx_issued_orders_status_date`(`status`, `order_date`),
+    PRIMARY KEY (`id`)
+) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+
+-- CreateTable
+CREATE TABLE `issued_order_items` (
+    `id` INTEGER NOT NULL AUTO_INCREMENT,
+    `issued_order_id` INTEGER NOT NULL,
+    `description` VARCHAR(500) NULL,
+    `item_description` TEXT NULL,
+    `quantity` DECIMAL(12, 3) NULL DEFAULT 1.000,
+    `unit` VARCHAR(20) NULL,
+    `unit_price` DECIMAL(12, 2) NULL DEFAULT 0.00,
+    `vat_rate` DECIMAL(5, 2) NULL DEFAULT 21.00,
+    `position` INTEGER NULL DEFAULT 0,
+
+    INDEX `issued_order_id`(`issued_order_id`),
+    PRIMARY KEY (`id`)
+) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+
+-- AddForeignKey
+ALTER TABLE `issued_orders` ADD CONSTRAINT `issued_orders_ibfk_1` FOREIGN KEY (`customer_id`) REFERENCES `customers`(`id`) ON DELETE RESTRICT ON UPDATE NO ACTION;
+
+-- AddForeignKey
+ALTER TABLE `issued_order_items` ADD CONSTRAINT `issued_order_items_ibfk_1` FOREIGN KEY (`issued_order_id`) REFERENCES `issued_orders`(`id`) ON DELETE CASCADE ON UPDATE NO ACTION;