Address remaining review feedback

- Use ParseIssueFilterStateIsClosed for ListProjects state parsing
- Add SortTypeProjectColumnSorting const, replace magic string
- Use GetIssueByRepoID and dedupe Add/Remove issue handlers
- Migrate Column.Sorting from int8 to int (drops 127-column limit, allows
  the API to expose a normal int without truncation)
- Introduce project_service.UpdateProject with optional.Option fields,
  use it from the API EditProject handler

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

models/migrations/v1_27/v332.go

@@ -0,0 +1,26 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_27
+
+import (
+	"code.gitea.io/gitea/models/migrations/base"
+
+	"xorm.io/xorm"
+	"xorm.io/xorm/schemas"
+)
+
+// WidenProjectBoardSorting changes project_board.sorting from int8 (TINYINT) to int (INTEGER)
+// so the public API can expose a regular int and lift the 127 column upper bound.
+func WidenProjectBoardSorting(x *xorm.Engine) error {
+	if x.Dialect().URI().DBType == schemas.SQLITE {
+		return nil
+	}
+	return base.ModifyColumn(x, "project_board", &schemas.Column{
+		Name:           "sorting",
+		SQLType:        schemas.SQLType{Name: "INT"},
+		Nullable:       false,
+		Default:        "0",
+		DefaultIsEmpty: false,
+	})
+}