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

db/migrate/tables/gitea_pull_requests.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+# -- 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.
+# ++
+
+require Rails.root.join("db/migrate/tables/base").to_s
+
+class Tables::GiteaPullRequests < Tables::Base
+  def self.table(migration)
+    create_table migration do |t|
+      t.references :gitea_user
+      t.references :merged_by
+
+      t.bigint :gitea_id
+      t.integer :number, null: false
+      t.string :gitea_html_url, null: false
+      t.string :state, null: false
+      t.string :repository, null: false
+      t.datetime :gitea_updated_at, precision: nil
+      t.string :title
+      t.text :body
+      t.boolean :draft
+      t.boolean :merged
+      t.datetime :merged_at, precision: nil
+      t.json :labels
+
+      t.timestamps precision: nil
+    end
+  end
+end

db/migrate/tables/gitea_pull_requests_work_packages.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+# -- 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.
+# ++
+
+require Rails.root.join("db/migrate/tables/base").to_s
+
+class Tables::GiteaPullRequestsWorkPackages < Tables::Base
+  def self.table(migration)
+    migration.create_join_table :gitea_pull_requests, :work_packages do |t|
+      t.index :gitea_pull_request_id, name: "gitea_pr_wp_pr_id"
+      t.index %i[gitea_pull_request_id work_package_id],
+              unique: true,
+              name: "unique_index_gitea_prs_wps_on_gitea_pr_id_and_wp_id"
+    end
+  end
+end

db/migrate/tables/gitea_users.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+# -- 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.
+# ++
+
+require Rails.root.join("db/migrate/tables/base").to_s
+
+class Tables::GiteaUsers < Tables::Base
+  def self.table(migration)
+    create_table migration do |t|
+      t.bigint :gitea_id, null: false
+      t.string :gitea_name, null: false
+      t.string :gitea_login, null: false
+      t.string :gitea_avatar_url, null: false
+
+      t.timestamps precision: nil
+    end
+  end
+end