home: zsh: add asynchronous prompt

And customize it so that it looks like the old one, because change is
*bad*.

home/zsh/default.nix

@@ -23,6 +23,15 @@
           sha256 = "sha256-DWVFBoICroKaKgByLmDEo4O+xo6eA8YO792g8t8R7kA=";
         };
       }
+      {
+        name = "agkozak-zsh-prompt";
+        src = fetchFromGitHub {
+          owner = "agkozak";
+          repo = "agkozak-zsh-prompt";
+          rev = "v3.9.0";
+          sha256 = "sha256-VTRL+8ph2eI7iPht15epkLggAgtLGxB3DORFTW5GrhE=";
+        };
+      }
     ];
 
     # Modal editing is life, but CLI benefits from emacs gymnastics
@@ -32,6 +41,17 @@
       ./completion-styles.zsh
       ./options.zsh
     ];
+
+    localVariables = {
+      # I like having the full path
+      AGKOZAK_PROMPT_DIRTRIM = 0;
+      # Because I *am* from EPITA
+      AGKOZAK_PROMPT_CHAR = [ "42sh$" "42sh#" ":" ];
+      # Easy on the eyes
+      AGKOZAK_COLORS_BRANCH_STATUS = "magenta";
+      # I don't like moving my eyes
+      AGKOZAK_LEFT_PROMPT_ONLY = 1;
+    };
   };
 
   # Fuzzy-wuzzy