feat(helpdesk): add Software Products page with BC contract type sync

Add a new Software-Produkte feature to the helpdesk module that syncs
contract types (Create_SaaS_License=true) from BC OData into a local
database table with a nightly scheduler job, providing a Grid.js list
page and detail/edit page for managing custom product names.

- DB migration 003: helpdesk_software_products table (code UNIQUE key)
- BcODataGateway: FS_Contract_Types entity with SaaS filter + fallback
- SoftwareProductRepository: upsert, listPaged, softDelete, updateName
- SoftwareProductSyncService: fetch → upsert → soft-delete lifecycle
- SoftwareProductSyncJobHandler: daily at 02:00 via scheduler platform
- SoftwareProductService: web UI business logic with validation
- Permission: helpdesk.software-products.manage (nav-gated)
- List page: Grid.js with Code, BC Description, Name, Status columns
- Detail page: Code/BC Description read-only, Name editable, PRG pattern
- i18n: de + en translation keys

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/helpdesk/migrations/003_create_software_products.sql

@@ -0,0 +1,14 @@
+CREATE TABLE IF NOT EXISTS `helpdesk_software_products` (
+    `id`              BIGINT UNSIGNED  NOT NULL AUTO_INCREMENT,
+    `code`            VARCHAR(30)      NOT NULL,
+    `bc_description`  VARCHAR(255)     NOT NULL DEFAULT '',
+    `name`            VARCHAR(255)     NOT NULL DEFAULT '',
+    `active`          TINYINT(1)       NOT NULL DEFAULT 1,
+    `synced_at`       DATETIME         NULL     DEFAULT NULL,
+    `created_at`      DATETIME         NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    `updated_at`      DATETIME         NULL     DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
+    PRIMARY KEY (`id`),
+    UNIQUE KEY `uniq_hsp_code` (`code`),
+    KEY `idx_hsp_active` (`active`),
+    KEY `idx_hsp_synced_at` (`synced_at`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;