env-manager: ui polish (#127)

* env-manager: migrate to pico 2.0.6

* env: option to hide children from ui

* introduce template hierarchy

* style: improve menu styling

* env: reorganize tasks, pull before install

---------

Co-authored-by: Giorgi Lekveishvili <lekva@gl-mbp-m1-max.local>
diff --git a/core/installer/tasks/activate.go b/core/installer/tasks/activate.go
index 0980dee..1333f28 100644
--- a/core/installer/tasks/activate.go
+++ b/core/installer/tasks/activate.go
@@ -13,15 +13,10 @@
 //go:embed env-tmpl
 var filesTmpls embed.FS
 
-type activateEnvTask struct {
-	basicTask
-	env Env
-	st  *state
-}
-
 func NewActivateEnvTask(env Env, st *state) Task {
 	return newSequentialParentTask(
-		fmt.Sprintf("Activate new %s instance", env.PCloudEnvName),
+		"Activate GitOps",
+		false,
 		AddNewEnvTask(env, st),
 		// TODO(gio): sync dodo-flux
 	)