Fix install-breaking and live-boot bugs, verified on real hardware

Boot-critical (each confirmed with a real boot/install cycle, not just
code review):

- Live ISO's liveuser shell is zsh, but Hyprland autostart was written
  to .bash_profile (never runs) — moved to .zprofile, and switched to
  start-hyprland (Hyprland's own watchdog wrapper; raw `exec Hyprland`
  is no longer the recommended launch method).
- copytoram (self-enables on most real hardware: non-optical boot +
  image < 4GiB + enough free RAM) unmounts /run/archiso/bootmnt, which
  unpackfs.conf and bos-copy-kernel both hardcoded as their source —
  broke the installer outright on real hardware, confirmed by forcing
  copytoram=y. Added a resolver step for unpackfs, and switched the
  kernel copy to /usr/lib/modules/$(uname -r)/vmlinuz (part of the live
  squashfs itself, unaffected by copytoram).
- BIOS installs got no bootloader — post-install.sh only ever ran the
  UEFI grub-install path despite BOS shipping bios.syslinux. Added a
  BIOS branch with disk auto-detection.
- @snapshots/@log/@cache were never real: iso/partition.conf's
  btrfsSubvolumes key isn't part of this Calamares version's partition
  module schema at all (same class of bug as the userShell fix below —
  silently ignored). Calamares only natively creates @ and @home.
  post-install.sh now creates the three subvolumes by hand after
  unpackfs, migrates existing /var/log + /var/cache content into them
  before mounting over, and adds the fstab entries — verified end to
  end on real hardware, including grub-btrfs generating bootable
  snapshot menu entries. The unmount step in the existing snapper
  create-config dance also gained retry + lazy-unmount fallback after
  a real chroot run hit a transient busy-mount race.
- Default shell was bash instead of zsh post-install: users.conf's
  top-level `userShell` key isn't part of this Calamares version's
  users module schema either — the real key is nested (user.shell).
- graphical-session.target ships RefuseManualStart=yes (systemd
  convention), so the earlier attempt to activate it from hyprland.lua
  silently failed and breadclipd (WantedBy=graphical-session.target)
  never started. Starts breadclipd.service directly instead.
- /etc/os-release was never set (showed "Arch Linux"); live boot never
  had quiet/splash/plymouth wired in (raw kernel scroll the whole
  time) despite BOS already shipping a complete bread-logo+spinner
  plymouth theme for the installed system.

Also: generalized build-local.sh's per-service skel baking (previously
only breadd.service was hand-committed; breadbox-sync/breadmill/
breadclipd never shipped), added the four new bakery packages to
BREAD_BINS, removed the redundant cliphist/fzf clipboard pipeline in
favor of breadclip, mirrored fastfetch's bread-logo config into skel,
and fixed a stale bos-update comment.

iso/airootfs/etc/skel/.config/hypr/hyprland.lua

@@ -125,7 +125,10 @@ hl.bind(mod .. " + slash",     hl.dsp.exec_cmd("bos-keybinds"))
 hl.bind(mod .. " + L",         hl.dsp.exec_cmd("loginctl lock-session"))
 hl.bind(mod .. " + F",         hl.dsp.window.fullscreen({ action = "toggle" }))
 hl.bind(mod .. " + V",         hl.dsp.window.float({ action = "toggle" }))
-hl.bind(mod .. " + SHIFT + V", hl.dsp.exec_cmd([[bash -c 'cliphist list | fzf --reverse --prompt="Clipboard > " | cliphist decode | wl-copy']]))
+-- breadclip (its own gtk4-layer-shell popup — not a TUI, so no terminal
+-- needed). Previously piped cliphist through fzf directly from the
+-- compositor with no terminal attached, which was a silent no-op.
+hl.bind(mod .. " + SHIFT + V", hl.dsp.exec_cmd("breadclip"))
 hl.bind(mod .. " + T",         hl.dsp.layout("togglesplit"))
 hl.bind(mod .. " + Tab",       hl.dsp.focus({ urgent_or_last = true }))
 hl.bind(mod .. " + N",         hl.dsp.exit())
@@ -198,8 +201,9 @@ hl.on("hyprland.start", function()
         "gsettings set org.gnome.desktop.interface icon-theme Papirus-Dark",
         "gsettings set org.gnome.desktop.interface cursor-theme Bibata-Modern-Ice",
         "gsettings set org.gnome.desktop.interface cursor-size 24",
-        -- Clipboard history daemon (feeds SUPER+V history picker via wl-paste).
-        "wl-paste --type text --watch cliphist store",
+        -- Clipboard history is breadclipd, a bakery-managed systemd --user
+        -- service (auto-started via skel — see build-local.sh's service bake)
+        -- rather than an exec-once here.
         "/usr/lib/polkit-gnome/polkit-gnome-authentication-agent-1",
         "awww-daemon",
         -- set the default wallpaper once the daemon is up (retry until ready)
@@ -210,8 +214,20 @@ hl.on("hyprland.start", function()
         -- to pick it up — that's how it gets HYPRLAND_INSTANCE_SIGNATURE to talk to Hyprland.
         "dbus-update-activation-environment --systemd WAYLAND_DISPLAY XDG_CURRENT_DESKTOP HYPRLAND_INSTANCE_SIGNATURE",
         "systemctl --user restart breadd",
+        -- graphical-session.target ships with RefuseManualStart=yes (systemd
+        -- convention — only a session manager like uwsm is meant to activate
+        -- it), confirmed on real hardware: `systemctl --user start
+        -- graphical-session.target` fails outright ("Operation refused").
+        -- BOS doesn't use uwsm, and nothing else activates that target, so
+        -- breadclipd (WantedBy=graphical-session.target) never started.
+        -- Start it directly instead. If more graphical-session.target
+        -- services show up later, add them here too.
+        "systemctl --user start breadclipd.service",
         "breadbar",
-        "breadbox-sync",
+        -- breadbox-sync is a Type=oneshot systemd --user service
+        -- (WantedBy=default.target, no Hyprland IPC dependency) — it
+        -- already runs on login via the unit baked into skel; exec'ing it
+        -- again here would just start it twice.
         "hypridle",
         -- first-boot onboarding (self-gates after the first run)
         "bos-welcome",