Initial commit: Maskan CRM backend

Independent FastAPI backend for Maskan CRM.

Owns contacts, organizations, leads, pipelines, activities, products,
quotes, users, permissions, audit records and first-party integration
credentials, with Alembic migrations against PostgreSQL.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

LICENSE

@@ -0,0 +1,20 @@
+MaskanX Proprietary License
+
+Copyright (c) 2026 MaskanX. All rights reserved.
+
+This software and associated documentation files (the "Software") are
+proprietary to MaskanX.
+
+You may use, copy, modify, deploy, and distribute the Software only with prior
+written permission from MaskanX or under a separate written agreement signed
+by MaskanX.
+
+No rights are granted to sublicense, sell, lease, rent, publish, host for third
+parties, or otherwise make the Software available to others except where
+expressly permitted in writing by MaskanX.
+
+The Software is provided "as is", without warranty of any kind, express or
+implied, including but not limited to the warranties of merchantability,
+fitness for a particular purpose, and noninfringement. In no event shall
+MaskanX be liable for any claim, damages, or other liability arising from use
+of the Software.