fix: avoid deleting peers on graceful close (#14165)

* fix: avoid deleting peers on graceful close

- Fixes an issue where a coordinator deletes all
  its peers on shutdown. This can cause disconnects
  whenever a coderd is redeployed.

coderd/database/queries.sql.go

@@ -7419,6 +7419,25 @@ func (q *sqlQuerier) GetTailnetTunnelPeerIDs(ctx context.Context, srcID uuid.UUI
 	return items, nil
 }
 
+const updateTailnetPeerStatusByCoordinator = `-- name: UpdateTailnetPeerStatusByCoordinator :exec
+UPDATE 
+	tailnet_peers
+SET
+	status = $2
+WHERE
+	coordinator_id = $1
+`
+
+type UpdateTailnetPeerStatusByCoordinatorParams struct {
+	CoordinatorID uuid.UUID     `db:"coordinator_id" json:"coordinator_id"`
+	Status        TailnetStatus `db:"status" json:"status"`
+}
+
+func (q *sqlQuerier) UpdateTailnetPeerStatusByCoordinator(ctx context.Context, arg UpdateTailnetPeerStatusByCoordinatorParams) error {
+	_, err := q.db.ExecContext(ctx, updateTailnetPeerStatusByCoordinator, arg.CoordinatorID, arg.Status)
+	return err
+}
+
 const upsertTailnetAgent = `-- name: UpsertTailnetAgent :one
 INSERT INTO
 	tailnet_agents (