Add modular dev environment installer, dotfiles, and desnap script

Adds a TUI-driven, rollback-capable installer (install/install.sh +
install/modules/*.sh) covering JS/Python/systems toolchains, dev tooling,
browsers, chat apps, GNOME extras, and misc setup (wakatime key, ssh/gpg
perms, apt mirror benchmarking), all sourced from each vendor's official
install method. bootstrap.sh stows the zsh/git/tmux/vscode dotfiles and
runs the installer; desnap.sh purges snapd and replaces default snaps with
apt/Flatpak equivalents.

install/modules/uv.sh

@@ -0,0 +1,6 @@
+install_uv() {
+  if has_cmd uv; then ok "uv already installed"; return; fi
+  rollback_push "rm -f '$HOME/.local/bin/uv' '$HOME/.local/bin/uvx'"
+  curl -LsSf https://astral.sh/uv/install.sh | sh
+  profile_add 'export PATH="$HOME/.local/bin:$PATH"'
+}