Make direct direnv loading default (#18536)

I've been running with direct direnv loading for a while now and haven't
experienced any significant issues other than #18473. Making it default
would make direnv integration more reliable and consistent. I've also
updated the docs a bit to ensure that they represent current status of
direnv integration

Release Notes:

- Made direnv integration use direct (`direnv export json`) mode by
default instead of relying on a shell hook, improving consistency and
reliability of direnv detection

crates/project/src/project_settings.rs

@@ -62,12 +62,9 @@ pub struct NodeBinarySettings {
 #[serde(rename_all = "snake_case")]
 pub enum DirenvSettings {
     /// Load direnv configuration through a shell hook
-    #[default]
     ShellHook,
     /// Load direnv configuration directly using `direnv export json`
-    ///
-    /// Warning: This option is experimental and might cause some inconsistent behavior compared to using the shell hook.
-    /// If it does, please report it to GitHub
+    #[default]
     Direct,
 }