feat(terminal): harden terminal abbreviations and functions

- Wrap Kitty-specific abbreviations and functions with $TERM checks

- Resurrect WezTerm abbreviations and wrap with $TERM_PROGRAM checks

- Add check_fish_deps function to list and verify all fish-related dependencies

- Update README to recommend Kitty and WezTerm and document requirements

- Improve fallback behavior for rg outside of Kitty

functions/clone.fish

@@ -2,6 +2,9 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
 function clone --wraps=clone-in-kitty --description 'alias clone=clone-in-kitty'
-  clone-in-kitty $argv
-        
+    if test "$TERM" != xterm-kitty
+        echo "Error: The 'clone' command requires Kitty terminal." >&2
+        return 1
+    end
+    clone-in-kitty $argv
 end