Initial commit: NexusOS project + desktop theme baseline

Captures the known-good state after theme consolidation and
consistency reconciliation:
- NexusOS GTK/xfwm4/icon theme assets (assets/themes, management/Mint-Y-Nexus)
- Tightened right-click menus, visible separators, no menu icons
- assets/themes/install-theme.sh: idempotent restore of all wiring
  (symlinks, xfconf xsettings+xfwm4, GTK 3/4 settings.ini)
- .gitignore excludes venv/ollama/models/runtime/db

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

amd_requirements.txt

@@ -0,0 +1,10 @@
+# --- Force AMD/ROCm Priority ---
+--index-url https://download.pytorch.org/whl/rocm7.2
+--extra-index-url https://pypi.org/simple
+
+-r requirements-base.txt
+
+# GPU Compute Stack
+torch
+torchaudio
+torchvision