chore: make AGPL license detectable (#467)

Replace the root LICENSE file's custom preamble with the verbatim AGPL-3.0 text so GitHub's license detector and directory scrapers recognize the repo as AGPL-3.0. The dual-license/commercial explanation moves to LICENSING.md.

LICENSE

@@ -1,22 +1,3 @@
-SnapOtter
-Copyright (C) 2025-present
-
-This software is dual-licensed:
-
-1. GNU Affero General Public License v3.0 (AGPLv3)
-   You may use, modify, and distribute this software under the terms of
-   the AGPLv3, the full text of which follows below.
-
-2. Commercial License
-   For use without AGPLv3 obligations (e.g., in proprietary products or
-   SaaS offerings without source disclosure), a commercial license is
-   available. Contact me for terms.
-
-Unless you have purchased a commercial license, your use of this software
-is governed by the AGPLv3.
-
---------------------------------------------------------------------------------
-
                     GNU AFFERO GENERAL PUBLIC LICENSE
                        Version 3, 19 November 2007
 

LICENSING.md

@@ -1,12 +1,17 @@
 # Licensing
 
-SnapOtter is open-core:
+SnapOtter is open-core and dual-licensed:
 
 - **All content in this repository is licensed under AGPL-3.0 (see `LICENSE`),
-  EXCEPT the contents of `packages/enterprise/`.**
+  EXCEPT the contents of `packages/enterprise/`, unless you have purchased a
+  commercial license from SnapOtter.**
 - `packages/enterprise/` is governed by the SnapOtter Commercial License
   (see `packages/enterprise/LICENSE`).
 
+For use without AGPL-3.0 obligations, such as proprietary products or SaaS
+offerings without source disclosure, contact SnapOtter for commercial license
+terms.
+
 The community edition is fully functional without any code from
 `packages/enterprise`: all tools, batch, pipelines, API keys, and single-node
 operation work without a license key. Enterprise features (see