fix(theme): set default to summer-night and fix scripts on live ISO

- Update lib/state-schema.nix to default both home and system themes to 'summer-night'.
- Fix 'nomarchy-theme-list' and 'nomarchy-theme-set-templates' to resolve themes and templates from '~/.local/share/nomarchy' instead of the obsolete '$NOMARCHY_PATH' (fixing failures on Live ISO).
- Update 'nomarchy-welcome' to properly convert Title Case theme display names back to kebab-case identifiers and add input validation to prevent crashes.
- Fix installer impermanence symlink by using a relative path ('../persist/etc/nixos'), ensuring it resolves during 'nixos-install' both inside and outside the chroot.
- Deploy '~/.XCompose' symlink via Home Manager and add 'nomarchy-restart-xcompose' to the menu.
- Relocate 'Nomarchy.ttf' to 'core/branding/' and move user-level scripts ('pkg-add', 'pkg-remove', 'env-update', 'preflight-migration') to 'features/scripts/utils/' to align with the distro architecture.
- Remove obsolete '$NOMARCHY_PATH' exports and redundant 'bashrc' template.
- Export theme templates via 'xdg.dataFile' for script accessibility.

core/home/config/nomarchy/default/bashrc

@@ -1,11 +0,0 @@
-# If not running interactively, don't do anything (leave this at the top of this file)
-[[ $- != *i* ]] && return
-
-# All the default Nomarchy aliases and functions
-# (don't mess with these directly, just overwrite them here!)
-source ~/.config/nomarchy/default/bash/rc
-
-# Add your own exports, aliases, and functions here.
-#
-# Make an alias for invoking commands you use constantly
-# alias p='python'

core/home/config/nomarchy/default/elephant/nomarchy_themes.lua

@@ -32,8 +32,7 @@ end
 function GetEntries()
   local entries = {}
   local user_theme_dir = os.getenv("HOME") .. "/.config/nomarchy/themes"
-  local nomarchy_path = os.getenv("NOMARCHY_PATH") or "/etc/nixos"
-  local default_theme_dir = nomarchy_path .. "/themes/palettes"
+  local default_theme_dir = os.getenv("HOME") .. "/.local/share/nomarchy/themes"
 
   local seen_themes = {}