Fix: tree CLI command cannot find existing trees (#5370)

The TreeEdit command (`tree --delete`, `tree --title`) always failed
with "Tree '<name>' does not exist.", because the tree lookup used the
literal string 'name' as the collection key instead of the $name
argument value:

    $tree = $this->tree_service->all()->get('name');

Replace with the variable so the lookup works as intended:

    $tree = $this->tree_service->all()->get($name);

Reproduce on main:

    php index.php tree --create --title=Demo demo
    php index.php tree --delete demo
    # → [ERROR] Tree 'demo' does not exist.

`tree --create` was unaffected because its happy path does not depend
on the lookup result.

1 files changed, 1 insertions, 1 deletions

diff --git a/app/Cli/Commands/TreeEdit.php b/app/Cli/Commands/TreeEdit.php
index 8fdb6f1855..e2d62ae326 100644
--- a/app/Cli/Commands/TreeEdit.php
+++ b/app/Cli/Commands/TreeEdit.php
@@ -73,7 +73,7 @@ final class TreeEdit extends AbstractCommand
             return Command::INVALID;
         }
 
-        $tree = $this->tree_service->all()->get('name');
+        $tree = $this->tree_service->all()->get($name);
 
         if ($create) {
             if ($tree instanceof Tree) {