Add OpenProject Gitea integration plugin

Implements a Gitea integration for OpenProject following the same
patterns as the bundled GitHub and GitLab integrations.

- Webhook endpoint at /webhooks/gitea with HMAC-SHA256 verification
- Handles pull_request and issue_comment events
- Links Gitea PRs to work packages via OP# references or URLs
- Posts journal comments on WPs for PR lifecycle events
- Gitea tab on the work package split view
- V3 API endpoint: GET /api/v3/work_packages/:id/gitea_pull_requests
- Admin settings UI for bot user and webhook secret
- Nightly cron job to clean up unlinked PR records

config/locales/js-en.yml

@@ -0,0 +1,55 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+---
+en:
+  js:
+    gitea_integration:
+      tab_header_pr:
+        copy_menu:
+          description: Copy git snippets to clipboard
+          label: Git snippets
+        create_pr:
+          description: Create a Pull Request
+          label: Create PR
+        git_actions:
+          branch_name: Branch name
+          cmd: Create branch with empty commit
+          commit_message: Commit message
+          copy_error: Copy failed!
+          copy_success: Copied!
+          title: Quick snippets for Git
+        title: "Pull requests"
+      tab_prs:
+        empty: There are no pull requests linked yet. Link an existing PR by using the code <code>OP#%{wp_id}</code> in the PR title/description or create a new PR.
+      updated_on: Updated on
+      work_packages:
+        tab_name: "Gitea"
+    work_packages:
+      tabs:
+        gitea: "Gitea"