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>

requirements-base.txt

@@ -0,0 +1,44 @@
+# --- Shared Base (GPU-agnostic) ---
+
+# AI Stack
+transformers
+accelerate
+bitsandbytes
+safetensors
+sentencepiece
+tokenizers
+huggingface-hub
+
+# API & Web Infrastructure
+fastapi
+uvicorn
+starlette
+pydantic
+pydantic_core
+anyio
+h11
+httptools
+watchfiles
+websockets
+wsproto
+
+# Data, UI & System Tools
+numpy
+scipy
+pandas
+psutil
+PySide6
+PySide6_Addons
+PySide6_Essentials
+shiboken6
+tqdm
+rich
+python-dotenv
+PyYAML
+
+# Documentation Support
+markdown-it-py
+MarkupSafe
+mdurl
+Pygments
+Jinja2