feat(api): add REST API for repository project boards

Cherry-pick of upstream PR go-gitea/gitea#37518 onto feat/projects-api.
The PR is itself a rebase of #36831 onto main, adapted for the
multi-projects-per-issue model added in #36784.

Endpoints (all under /repos/{owner}/{repo}/projects...):
  GET    .                                 list projects
  POST   .                                 create project
  GET    /{id}                              get project
  PATCH  /{id}                              update project
  DELETE /{id}                              delete project
  GET    /{id}/columns                      list columns
  POST   /{id}/columns                      create column
  PATCH  /columns/{id}                      update column
  DELETE /columns/{id}                      delete column
  GET    /columns/{id}/issues               list issues in column
  POST   /columns/{id}/issues/{issue_id}    add/move issue to column
  DELETE /columns/{id}/issues/{issue_id}    remove issue from column
  POST   /columns/{id}/issues/{issue_id}/move  move between columns

Source: https://github.com/go-gitea/gitea/pull/37518

modules/indexer/issues/dboptions.go

@@ -97,7 +97,7 @@ func ToSearchOptions(keyword string, opts *issues_model.IssuesOptions) *SearchOp
 		searchOpt.SortBy = SortByDeadlineAsc
 	case "farduedate":
 		searchOpt.SortBy = SortByDeadlineDesc
-	case "priority", "priorityrepo", "project-column-sorting":
+	case "priority", "priorityrepo", issues_model.SortTypeProjectColumnSorting:
 		// Unsupported sort type for search
 		fallthrough
 	default:

modules/structs/project.go

@@ -7,27 +7,101 @@ import (
 	"time"
 )
 
-// Project represents a project
+// Project represents a project.
+//
+// Gitea projects can only contain issues — note cards and pull requests are
+// not modeled as project items.
+//
 // swagger:model
 type Project struct {
-	// ID is the unique identifier for the project
-	ID int64 `json:"id"`
-	// Title is the title of the project
-	Title string `json:"title"`
-	// Description provides details about the project
-	Description string `json:"description"`
-	// OwnerID is the owner of the project (for org-level projects)
-	OwnerID int64 `json:"owner_id,omitempty"`
-	// RepoID is the repository this project belongs to (for repo-level projects)
-	RepoID int64 `json:"repo_id,omitempty"`
-	// CreatorID is the user who created the project
-	CreatorID int64 `json:"creator_id"`
-	// IsClosed indicates if the project is closed
-	IsClosed bool `json:"is_closed"`
+	ID          int64     `json:"id"`
+	Title       string    `json:"title"`
+	Description string    `json:"description"`
+	OwnerID     int64     `json:"owner_id,omitempty"`
+	RepoID      int64     `json:"repo_id,omitempty"`
+	Creator     *User     `json:"creator,omitempty"`
+	State       StateType `json:"state"`
+	// Template type: "none", "basic_kanban" or "bug_triage"
+	TemplateType string `json:"template_type"`
+	// Card type: "text_only" or "images_and_text"
+	CardType string `json:"card_type"`
+	// Project type: "individual", "repository" or "organization"
+	Type            string `json:"type"`
+	NumOpenIssues   int64  `json:"num_open_issues,omitempty"`
+	NumClosedIssues int64  `json:"num_closed_issues,omitempty"`
+	NumIssues       int64  `json:"num_issues,omitempty"`
 	// swagger:strfmt date-time
-	Created time.Time `json:"created_at"`
+	CreatedAt time.Time `json:"created_at"`
 	// swagger:strfmt date-time
-	Updated time.Time `json:"updated_at"`
+	UpdatedAt time.Time `json:"updated_at"`
 	// swagger:strfmt date-time
-	Closed *time.Time `json:"closed_at,omitempty"`
+	ClosedAt *time.Time `json:"closed_at,omitempty"`
+	HTMLURL  string     `json:"html_url,omitempty"`
+}
+
+// CreateProjectOption represents options for creating a project
+// swagger:model
+type CreateProjectOption struct {
+	// required: true
+	Title       string `json:"title" binding:"Required"`
+	Description string `json:"description"`
+	// Template type: "none", "basic_kanban" or "bug_triage"
+	TemplateType string `json:"template_type"`
+	// Card type: "text_only" or "images_and_text"
+	CardType string `json:"card_type"`
+}
+
+// EditProjectOption represents options for editing a project
+// swagger:model
+type EditProjectOption struct {
+	Title       *string `json:"title,omitempty"`
+	Description *string `json:"description,omitempty"`
+	// Card type: "text_only" or "images_and_text"
+	CardType *string    `json:"card_type,omitempty"`
+	State    *StateType `json:"state,omitempty"`
+}
+
+// ProjectColumn represents a project column (board)
+// swagger:model
+type ProjectColumn struct {
+	ID        int64  `json:"id"`
+	Title     string `json:"title"`
+	Default   bool   `json:"default"`
+	Sorting   int    `json:"sorting"`
+	Color     string `json:"color,omitempty"`
+	ProjectID int64  `json:"project_id"`
+	Creator   *User  `json:"creator,omitempty"`
+	NumIssues int64  `json:"num_issues,omitempty"`
+	// swagger:strfmt date-time
+	CreatedAt time.Time `json:"created_at"`
+	// swagger:strfmt date-time
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+// CreateProjectColumnOption represents options for creating a project column
+// swagger:model
+type CreateProjectColumnOption struct {
+	// required: true
+	Title string `json:"title" binding:"Required"`
+	// Column color in 6-digit hex format, e.g. #FF0000
+	Color string `json:"color,omitempty"`
+}
+
+// EditProjectColumnOption represents options for editing a project column
+// swagger:model
+type EditProjectColumnOption struct {
+	Title *string `json:"title,omitempty"`
+	// Column color in 6-digit hex format, e.g. #FF0000
+	Color   *string `json:"color,omitempty"`
+	Sorting *int    `json:"sorting,omitempty"`
+}
+
+// MoveProjectIssueOption represents options for moving an issue between columns
+// swagger:model
+type MoveProjectIssueOption struct {
+	// Target column to move the issue into
+	// required: true
+	ColumnID int64 `json:"column_id" binding:"Required"`
+	// Optional sorting position within the target column
+	Sorting *int64 `json:"sorting,omitempty"`
 }