Trim over-commented Chunk 3+/4 work

A pass over the install scripts, dev-tools commands, and Hyprland Lua
files that I had stuffed with explain-everything preambles. Most of
those rationales (which files ship where, why hyprctl setenv doesn't
suffice, etc.) belong in commit messages or PR descriptions, not in
code people have to read forever. Kept the few comments that document
genuinely non-obvious behaviour: the keybind-env reason for hl.env in
envs.lua, why the runtime PAM seds stay scripted in
increase-lockout-limit, the chroot/--now distinction in chroot.sh, and
the dev-pkg-test split-install reason.

config/hypr/hyprland.lua

@@ -1,10 +1,6 @@
 -- Learn how to configure Hyprland: https://wiki.hypr.land/Configuring/Start/
 
--- Force re-evaluation of Omarchy modules on every hyprctl reload. Lua caches
--- already-required modules in package.loaded, so without this clear, changes
--- to default/hypr/*.lua (and user ~/.config/hypr/*.lua) in a checkout wouldn't
--- take effect after `hyprctl reload` even though hyprland.lua re-runs.
--- Cheap: package.loaded is small.
+-- Drop cached omarchy modules so hyprctl reload re-reads them from disk.
 for k in pairs(package.loaded) do
   if k:match("^default%.hypr") or k:match("^hypr%.") then
     package.loaded[k] = nil