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>

starship.toml

@@ -0,0 +1,32 @@
+# Starship - Standard sane config
+# Path: ~/.config/starship.toml
+
+format = "$directory$git_branch$git_status$line_break$character"
+add_newline = true
+
+[character]
+success_symbol = "[❯](bold green)"
+error_symbol = "[❯](bold red)"
+
+[directory]
+truncation_length = 3
+truncation_symbol = "…/"
+style = "bold blue"
+
+[git_branch]
+symbol = " "
+style = "bold purple"
+
+[git_status]
+style = "red"
+format = '([$all_status$ahead_behind]($style) )'
+conflicted = "=${count}"
+ahead = "⇡${count}"
+behind = "⇣${count}"
+diverged = "⇕⇡${ahead_count}⇣${behind_count}"
+untracked = "?${count}"
+stashed = "*${count}"
+modified = "!${count}"
+staged = "+${count}"
+renamed = ">${count}"
+deleted = "x${count}"