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.

bin/omarchy-dev-pkg-test

@@ -48,7 +48,7 @@ trap 'rm -rf "$build_dir"' EXIT
 
 cp -a "$PKGBUILD_DIR/." "$build_dir/"
 
-# Mark the build with a versioned dev pkgver so pacman -Q makes the source obvious.
+# pkgver=dev.<sha>[.dirty] so pacman -Q makes the source obvious.
 short_sha=$(git -C "$CHECKOUT" rev-parse --short HEAD 2>/dev/null || echo "local")
 dirty=""
 if [[ -d "$CHECKOUT/.git" ]] && [[ -n "$(git -C "$CHECKOUT" status --porcelain)" ]]; then
@@ -65,11 +65,9 @@ echo
 cd "$build_dir"
 OMARCHY_SRC="$CHECKOUT" makepkg -s --skipchecksums --noconfirm "${@:3}"
 
-# Install separately so we can pass --overwrite='*' to pacman. In dev mode
-# the package commonly conflicts with files left behind by previous
-# script-installed Omarchy versions (plymouth themes, /etc drop-ins,
-# sudoers, etc.). makepkg -i forwards a fixed set of flags to pacman and
-# doesn't expose --overwrite.
+# Install separately so we can pass --overwrite='*' (makepkg -i can't).
+# Dev builds frequently conflict with files left behind by previous
+# script-installed Omarchy versions; the build is the authoritative state.
 built_pkg=$(ls -t "$build_dir"/*.pkg.tar.* 2>/dev/null | grep -v '\.sig$' | head -1)
 if [[ -z $built_pkg ]]; then
   echo "Error: no built package found in $build_dir" >&2