feat: add app status tracking to the backend (#17163)

This does ~95% of the backend work required to integrate the AI work.

Most left to integrate from the tasks branch is just frontend, which
will be a lot smaller I believe.

The real difference between this branch and that one is the abstraction
-- this now attaches statuses to apps, and returns the latest status
reported as part of a workspace.

This change enables us to have a similar UX to in the tasks branch, but
for agents other than Claude Code as well. Any app can report status
now.

codersdk/workspaceapps.go

@@ -1,6 +1,8 @@
 package codersdk
 
 import (
+	"time"
+
 	"github.com/google/uuid"
 )
 
@@ -13,6 +15,14 @@ const (
 	WorkspaceAppHealthUnhealthy    WorkspaceAppHealth = "unhealthy"
 )
 
+type WorkspaceAppStatusState string
+
+const (
+	WorkspaceAppStatusStateWorking  WorkspaceAppStatusState = "working"
+	WorkspaceAppStatusStateComplete WorkspaceAppStatusState = "complete"
+	WorkspaceAppStatusStateFailure  WorkspaceAppStatusState = "failure"
+)
+
 var MapWorkspaceAppHealths = map[WorkspaceAppHealth]struct{}{
 	WorkspaceAppHealthDisabled:     {},
 	WorkspaceAppHealthInitializing: {},
@@ -75,6 +85,9 @@ type WorkspaceApp struct {
 	Health      WorkspaceAppHealth `json:"health"`
 	Hidden      bool               `json:"hidden"`
 	OpenIn      WorkspaceAppOpenIn `json:"open_in"`
+
+	// Statuses is a list of statuses for the app.
+	Statuses []WorkspaceAppStatus `json:"statuses"`
 }
 
 type Healthcheck struct {
@@ -85,3 +98,20 @@ type Healthcheck struct {
 	// Threshold specifies the number of consecutive failed health checks before returning "unhealthy".
 	Threshold int32 `json:"threshold"`
 }
+
+type WorkspaceAppStatus struct {
+	ID                 uuid.UUID               `json:"id" format:"uuid"`
+	CreatedAt          time.Time               `json:"created_at" format:"date-time"`
+	WorkspaceID        uuid.UUID               `json:"workspace_id" format:"uuid"`
+	AgentID            uuid.UUID               `json:"agent_id" format:"uuid"`
+	AppID              uuid.UUID               `json:"app_id" format:"uuid"`
+	State              WorkspaceAppStatusState `json:"state"`
+	NeedsUserAttention bool                    `json:"needs_user_attention"`
+	Message            string                  `json:"message"`
+	// URI is the URI of the resource that the status is for.
+	// e.g. https://github.com/org/repo/pull/123
+	// e.g. file:///path/to/file
+	URI string `json:"uri"`
+	// Icon is an external URL to an icon that will be rendered in the UI.
+	Icon string `json:"icon"`
+}