Refactor bash config and env vars, set Zed as git editor

- Move environment variable exports from sessionVariables to bashrc
- Add more robust sourcing of .profile and .bashrc.local
- Improve SSH_AUTH_SOCK override logic for 1Password
- Remove redundant path and pyenv logic from profileExtra
- Set git core.editor to "zed" instead of "nvim"
- Add DOTFILES_PATH to global session variables

config/git.nix

@@ -23,7 +23,7 @@
       };
 
       core = {
-        editor = "nvim";
+        editor = "zed";
         autocrlf = false;
         filemode = true;
         ignorecase = false;