chore(license): add copyright/SPDX headers to zoxide files

- Add copyright + SPDX header to functions/zoxide.fish and
  conf.d/zoxide.fish (modified from original, owned by Rootiest)
- Add sourced-from attribution to completions/zoxide.fish
  (unmodified from icezyclon/zoxide.fish, MIT)

completions/zoxide.fish

@@ -1,3 +1,5 @@
+# Sourced from icezyclon/zoxide.fish (MIT)
+
 set -l commands add help import init query remove
 
 # disable normal all-files completion

conf.d/zoxide.fish

@@ -1,3 +1,5 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
 # Adapted from icezyclon/zoxide.fish (MIT)
 # Heavily customized for Fish 4.x compatibility and performance
 

functions/zoxide.fish

@@ -1,3 +1,5 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
 # Adapted from icezyclon/zoxide.fish (MIT)
 # Heavily customized for Fish 4.x compatibility and performance