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.

etc/profile.d/omarchy.sh

@@ -1,14 +1,7 @@
-# Source /etc/omarchy.conf first so dev-link or other system overrides can
-# pre-set OMARCHY_PATH (and anything else) before the defaults run.
-# install.sh's script-mode export still wins because /etc/omarchy.conf uses
-# the same :- guard.
 [ -f /etc/omarchy.conf ] && . /etc/omarchy.conf
 export OMARCHY_PATH="${OMARCHY_PATH:-/usr/share/omarchy}"
 
-# Prepend $OMARCHY_PATH/bin if it exists. In normal package mode this is a
-# no-op: bins ship to /usr/bin (already on PATH), and /usr/share/omarchy/bin
-# doesn't exist. When omarchy-dev-link is active OMARCHY_PATH points at a
-# local checkout, whose bin/ then overrides the /usr/bin copies.
+# omarchy-dev-link: prepend checkout bin/ so it shadows /usr/bin/omarchy-*.
 case ":$PATH:" in
   *":$OMARCHY_PATH/bin:"*) ;;
   *) [ -d "$OMARCHY_PATH/bin" ] && export PATH="$OMARCHY_PATH/bin:$PATH" ;;