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.go

@@ -0,0 +1,85 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"code.gitea.io/gitea/models/project"
+	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/builder"
+	"xorm.io/xorm"
+)
+
+// CheckProjectColumnsConsistency ensures there is exactly one default board per project present
+func CheckProjectColumnsConsistency(x *xorm.Engine) error {
+	sess := x.NewSession()
+	defer sess.Close()
+
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	limit := setting.Database.IterateBufferSize
+	if limit <= 0 {
+		limit = 50
+	}
+
+	start := 0
+
+	for {
+		var projects []project.Project
+		if err := sess.SQL("SELECT DISTINCT `p`.`id`, `p`.`creator_id` FROM `project` `p` WHERE (SELECT COUNT(*) FROM `project_board` `pb` WHERE `pb`.`project_id` = `p`.`id` AND `pb`.`default` = ?) != 1", true).
+			Limit(limit, start).
+			Find(&projects); err != nil {
+			return err
+		}
+
+		if len(projects) == 0 {
+			break
+		}
+		start += len(projects)
+
+		for _, p := range projects {
+			var boards []project.Board
+			if err := sess.Where("project_id=? AND `default` = ?", p.ID, true).OrderBy("sorting").Find(&boards); err != nil {
+				return err
+			}
+
+			if len(boards) == 0 {
+				if _, err := sess.Insert(project.Board{
+					ProjectID: p.ID,
+					Default:   true,
+					Title:     "Uncategorized",
+					CreatorID: p.CreatorID,
+				}); err != nil {
+					return err
+				}
+				continue
+			}
+
+			var boardsToUpdate []int64
+			for id, b := range boards {
+				if id > 0 {
+					boardsToUpdate = append(boardsToUpdate, b.ID)
+				}
+			}
+
+			if _, err := sess.Where(builder.Eq{"project_id": p.ID}.And(builder.In("id", boardsToUpdate))).
+				Cols("`default`").Update(&project.Board{Default: false}); err != nil {
+				return err
+			}
+		}
+
+		if start%1000 == 0 {
+			if err := sess.Commit(); err != nil {
+				return err
+			}
+			if err := sess.Begin(); err != nil {
+				return err
+			}
+		}
+	}
+
+	return sess.Commit()
+}