Self-hosted auto-updates from Gitea via PUC + proprietary licence

Vendors YahnisElsts/plugin-update-checker v5.7 under vendor/ and wires
it to poll updates.json on the repo main branch. WP surfaces new
versions via Dashboard → Updates on its normal twice-daily cadence.

PUC is vendored (not a submodule) so Gitea's archive/main.zip — the
download target — includes it.

Also relicenses from GPL-2.0-or-later to a proprietary licence granting
use only to authorised sites, with all other rights reserved. Plugin
URI + Author URI switched from the placeholder github.com URL to the
canonical Gitea repo.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

LICENSE

@@ -0,0 +1,47 @@
+ATT Consent — Proprietary Software License
+
+Copyright (c) 2026 Steve Hanlon. All rights reserved.
+
+This software and its source code are the confidential and proprietary
+property of the copyright holder. No rights are granted except as
+expressly set out below.
+
+1. Permitted use.
+   Sites that have been explicitly authorised in writing by the copyright
+   holder ("Authorised Sites") may install, run, and receive automatic
+   updates of this software solely for the operation of that Authorised
+   Site. No other use is permitted.
+
+2. Restrictions.
+   Except as permitted above, you may not:
+     (a) copy, modify, merge, publish, distribute, sublicense, sell,
+         rent, lease, or otherwise transfer the software or any portion
+         of it;
+     (b) reverse engineer, decompile, or disassemble the software,
+         except to the extent that such activity is expressly permitted
+         by applicable law notwithstanding this limitation;
+     (c) remove or alter any copyright, trademark, or other proprietary
+         notices in the software.
+
+3. Third-party components.
+   This distribution includes the Plugin Update Checker library by
+   Janis Elsts, which is licensed under the MIT License. See
+   vendor/plugin-update-checker/license.txt for that license text. The
+   present proprietary license applies only to the balance of the
+   software authored by the copyright holder.
+
+4. No warranty.
+   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 THE COPYRIGHT HOLDER BE LIABLE
+   FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+   CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+   WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+5. Termination.
+   Any use in breach of this license terminates the licence
+   automatically. On termination you must uninstall the software and
+   destroy all copies in your possession.
+
+For licensing enquiries, contact the copyright holder.