feat(127): erli integration foundation

Phase 127 complete:

- add global Erli settings schema and encrypted API key repository

- add real read-only Erli API connection test and settings UI

- expose Erli in integrations hub and update PAUL/docs state

database/migrations/20260515_000114_create_erli_integration_settings.sql

@@ -0,0 +1,28 @@
+CREATE TABLE IF NOT EXISTS `erli_integration_settings` (
+    `id` TINYINT UNSIGNED NOT NULL PRIMARY KEY,
+    `integration_id` INT UNSIGNED NULL,
+    `api_key_encrypted` TEXT NULL,
+    `account_label` VARCHAR(128) NULL,
+    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    `updated_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    UNIQUE KEY `erli_integration_settings_integration_unique` (`integration_id`),
+    CONSTRAINT `erli_integration_settings_integration_fk`
+        FOREIGN KEY (`integration_id`) REFERENCES `integrations` (`id`)
+        ON DELETE CASCADE ON UPDATE CASCADE
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+INSERT INTO `integrations` (`type`, `name`, `base_url`, `timeout_seconds`, `is_active`, `created_at`, `updated_at`)
+VALUES ('erli', 'Erli', 'https://erli.pl/svc/shop-api', 15, 1, NOW(), NOW())
+ON DUPLICATE KEY UPDATE
+    `base_url` = VALUES(`base_url`),
+    `timeout_seconds` = VALUES(`timeout_seconds`),
+    `updated_at` = VALUES(`updated_at`);
+
+INSERT INTO `erli_integration_settings` (`id`, `integration_id`, `created_at`, `updated_at`)
+SELECT 1, `id`, NOW(), NOW()
+FROM `integrations`
+WHERE `type` = 'erli' AND `name` = 'Erli'
+LIMIT 1
+ON DUPLICATE KEY UPDATE
+    `integration_id` = VALUES(`integration_id`),
+    `updated_at` = VALUES(`updated_at`);