Add default board to new projects, remove uncategorized pseudo-board (#29874)

On creation of an empty project (no template) a default board will be
created instead of falling back to the uneditable pseudo-board.

Every project now has to have exactly one default boards. As a
consequence, you cannot unset a board as default, instead you have to
set another board as default. Existing projects will be modified using a
cron job, additionally this check will run every midnight by default.

Deleting the default board is not allowed, you have to set another board
as default to do it.

Fixes #29873
Fixes #14679 along the way
Fixes #29853

Co-authored-by: delvh <dev.lh@web.de>
(cherry picked from commit e5160185ed65fd1c2bcb2fc7dc7e0b5514ddb299)

Conflicts:
	options/locale/locale_en-US.ini
	trivial conflict because Forgejo strings do not have
	surrounding double quotes

models/migrations/v1_22/v292_test.go

@@ -0,0 +1,44 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/project"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_CheckProjectColumnsConsistency(t *testing.T) {
+	// Prepare and load the testing database
+	x, deferable := base.PrepareTestEnv(t, 0, new(project.Project), new(project.Board))
+	defer deferable()
+	if x == nil || t.Failed() {
+		return
+	}
+
+	assert.NoError(t, CheckProjectColumnsConsistency(x))
+
+	// check if default board was added
+	var defaultBoard project.Board
+	has, err := x.Where("project_id=? AND `default` = ?", 1, true).Get(&defaultBoard)
+	assert.NoError(t, err)
+	assert.True(t, has)
+	assert.Equal(t, int64(1), defaultBoard.ProjectID)
+	assert.True(t, defaultBoard.Default)
+
+	// check if multiple defaults were removed
+	expectDefaultBoard, err := project.GetBoard(db.DefaultContext, 2)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(2), expectDefaultBoard.ProjectID)
+	assert.True(t, expectDefaultBoard.Default)
+
+	expectNonDefaultBoard, err := project.GetBoard(db.DefaultContext, 3)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(2), expectNonDefaultBoard.ProjectID)
+	assert.False(t, expectNonDefaultBoard.Default)
+}