refactor: major architectural restructure for theme-centric organization

Theme System:
- Move all theme app configs to apps/ subdirectory (20 themes)
- Add theme-loader.nix for dynamic theme config deployment
- Simplify stylix.nix to focus on base theming only

Override System:
- Add overrides.nix for file-based config overrides
- Add behavior-configs.nix for non-visual configuration
- Split hypr/nomarchy.conf into behavior vs visual sections

Module Improvements:
- Add lib.mkDefault to all customizable settings
- Add modules/lib/ with shared utilities and state schema
- Update all home and system modules for downstream overridability

Installer:
- New minimal TTY installer (installer/install.sh)
- Golden path: BTRFS + LUKS2 (disko-golden.nix)
- New installer-iso.nix for TTY-only installation
- Keep graphical installer as installerIsoGraphical option

Cleanup:
- Remove obsolete install.sh, disko-ext4.nix, install-nomarchy.sh
- Update live-iso.nix references
- Add .claude/ to .gitignore for local IDE settings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

assets/themes/lumon/apps/hyprland.conf

@@ -0,0 +1,26 @@
+$activeBorderColor = rgb(f2fcff)
+$activeShadowColor = rgb(6fb8e3)
+$inactiveBorderColor = rgba(30486099)
+$inactiveShadowColor = rgba(30486077)
+
+general {
+    col.active_border = $activeBorderColor
+    col.inactive_border = $inactiveBorderColor
+    gaps_in = 8
+    gaps_out = 16
+}
+
+group {
+    col.border_active = $activeBorderColor
+    col.border_inactive = $inactiveBorderColor
+}
+
+decoration {
+    shadow {
+      enabled = true
+      range = 16
+      render_power = 4
+      color = $activeShadowColor
+      color_inactive = $inactiveShadowColor
+    }
+}