nu: better zoxide integration

will not complain if zoxide missing

src/.config/nushell/.gitignore

@@ -0,0 +1 @@
+zoxide.nu

src/.config/nushell/config.nu

@@ -713,4 +713,5 @@ $env.config = {
     ]
 }
 
-source ~/.config/nushell/zoxide.nu
+const zoxide_conf = "~/.config/nushell/zoxide.nu"
+source $zoxide_conf

src/.config/nushell/env.nu

@@ -95,4 +95,6 @@ $env.NU_PLUGIN_DIRS = [
 # To load from a custom file you can use:
 # source ($nu.default-config-dir | path join 'custom.nu')
 
-zoxide init nushell | save -f ~/.config/nushell/zoxide.nu
+if (which zoxide | length) > 0 {
+    zoxide init nushell | save -f ~/.config/nushell/zoxide.nu
+}

src/.config/nushell/zoxide.nu

@@ -0,0 +1,6 @@
+# DUMMY FILE for systems that do not have zoxide installed
+
+# nu doesn't like sourcing files conditionally, so we can't just have it ignore if zoxide.nu does not exist
+# watch issue: https://github.com/nushell/nushell/issues/8214
+
+# zoxide will overwrite this if it exists