feat: suspend instance improvements (#13861)

* feat(backend): dead instance detection

* feat(backend): suspend type detection

* feat(frontend): show suspend reason on frontend

* feat(backend): resume federation automatically if the server is automatically suspended

* docs(changelog): 配信停止まわりの改善

* lint: fix lint errors

* Update packages/frontend/src/pages/instance-info.vue

* lint: fix lint error

* chore: suspendedState => suspensionState

---------

Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>

packages/backend/src/models/json-schema/federation-instance.ts

@@ -45,6 +45,11 @@ export const packedFederationInstanceSchema = {
 			type: 'boolean',
 			optional: false, nullable: false,
 		},
+		suspensionState: {
+			type: 'string',
+			nullable: false, optional: false,
+			enum: ['none', 'manuallySuspended', 'goneSuspended', 'autoSuspendedForNotResponding'],
+		},
 		isBlocked: {
 			type: 'boolean',
 			optional: false, nullable: false,