chore: clean up dotfiles and add gitignore whitelist

Switch to whitelist-based .gitignore to only track essential configs:
nvim, yazi, kitty, zsh, ideavim, karabiner, tmux, scripts, starship.
Remove history, compiled files, and plugin dirs from tracking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

kitty/toggle_blur.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+CONFIG_FILE="/Users/thomasnaderer/.config/kitty/kitty.conf"
+
+# Check current blur setting
+current_blur=$(grep "^background_blur" "$CONFIG_FILE" | awk '{print $2}')
+
+if [ "$current_blur" = "0" ] || [ -z "$current_blur" ]; then
+    # Currently no blur, enable it
+    sed -i '' 's/^background_blur.*/background_blur 20/' "$CONFIG_FILE"
+    echo "Background blur enabled"
+else
+    # Currently blurred, disable it
+    sed -i '' 's/^background_blur.*/background_blur 0/' "$CONFIG_FILE"
+    echo "Background blur disabled"
+fi
+
+# Reload kitty configuration
+/opt/homebrew/bin/kitty @ load-config