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

assets/settings/default.json

@@ -599,13 +599,11 @@
     }
   },
   // Configuration for how direnv configuration should be loaded. May take 2 values:
-  // 1. Load direnv configuration through the shell hook, works for POSIX shells and fish.
-  //      "load_direnv": "shell_hook"
-  // 2. Load direnv configuration using `direnv export json` directly.
-  //    This can help with some shells that otherwise would not detect
-  //    the direnv environment, such as nushell or elvish.
+  // 1. Load direnv configuration using `direnv export json` directly.
   //      "load_direnv": "direct"
-  "load_direnv": "shell_hook",
+  // 2. Load direnv configuration through the shell hook, works for POSIX shells and fish.
+  //      "load_direnv": "shell_hook"
+  "load_direnv": "direct",
   "inline_completions": {
     // A list of globs representing files that inline completions should be disabled for.
     "disabled_globs": [".env"]