feat: ghostty -> havoc, fish -> yash, dwl -> river-classic, more minimal rofi configuration ; fix: nvim rust-analyzer ; docs: update preview screenshot

host/pc/common/river.nix

@@ -0,0 +1,7 @@
+{ ... }:
+{
+  programs.river-classic = {
+    enable = true;
+    xwayland.enable = true;
+  };
+}