fix(warehouse): add migration for warehouse permissions

The warehouse module v1.8.0 deploy created the warehouse tables via Prisma
migration but left the corresponding permissions (warehouse.view/operate/
manage/inventory) and admin role assignments un-inserted, because those
rows only existed in prisma/seed.ts, which is dev-only and cannot be run
against production.

This migration inserts the same 4 permissions seed.ts would (with
identical display_name and description) and assigns them to the admin
role. INSERT IGNORE makes it idempotent and preserves existing role
assignments. No data is modified or deleted.

Also strengthens CLAUDE.md: every database change or manipulation must
be a tracked Prisma migration. No external SQL, no seed-only data,
no manual fixes — reviewable, reversible, reproducible from a fresh
checkout.

prisma/migrations/20260603230000_add_warehouse_permissions/migration.sql

@@ -0,0 +1,29 @@
+-- Add warehouse module permissions and assign them to the admin role.
+-- These rows used to be created by `prisma/seed.ts`, which is dev-only and
+-- must not be run against production (per CLAUDE.md). This migration is
+-- idempotent: re-running it is a no-op.
+--
+-- The 4 permissions match `prisma/seed.ts` lines 284-308 exactly.
+
+-- 1. Insert the 4 warehouse permissions (INSERT IGNORE skips on duplicate
+--    name, so re-running the migration is safe).
+INSERT IGNORE INTO `permissions` (`name`, `display_name`, `module`, `description`, `created_at`) VALUES
+  ('warehouse.view',      'Zobrazit sklad',     'warehouse', 'Prohlížet stav skladu, položky, reporty a historii pohybů', NOW()),
+  ('warehouse.operate',   'Příjem a výdej',     'warehouse', 'Vytvářet a potvrzovat příjmy, výdeje a rezervace',          NOW()),
+  ('warehouse.manage',    'Správa skladu',      'warehouse', 'Spravovat katalog materiálů, dodavatele, lokace a kategorie', NOW()),
+  ('warehouse.inventory', 'Inventura',          'warehouse', 'Vytvářet a potvrzovat inventurní sčítkání',                  NOW());
+
+-- 2. Assign all 4 permissions to the admin role. INSERT IGNORE on the
+--    composite primary key (role_id, permission_id) makes this idempotent
+--    and preserves any other role assignments that already exist.
+INSERT IGNORE INTO `role_permissions` (`role_id`, `permission_id`)
+SELECT r.id, p.id
+FROM   `roles` r
+CROSS  JOIN `permissions` p
+WHERE  r.name = 'admin'
+  AND  p.name IN (
+    'warehouse.view',
+    'warehouse.operate',
+    'warehouse.manage',
+    'warehouse.inventory'
+  );