feat: Add HF Spaces deployment packages to requirements.txt

Added Packages:
- accelerate==0.26.1: GPU memory optimization and model loading
- huggingface-hub>=0.19.0: HF Hub API, model download, authentication
- spaces: ZeroGPU support for dynamic GPU allocation

Organization:
- Add section comments for clarity
- Group by functionality (ML, Tokenizers, HF, Environment, GPU)
- Maintain compatibility with HF Spaces hosting requirements

Technical Details:
- accelerate: Required for large model loading with low_cpu_mem_usage
- huggingface-hub: Enables cache management, token auth, model downloads
- spaces: Optional package for ZeroGPU, graceful fallback on local

Compatibility:
- All packages tested on local environment
- ZeroGPU (spaces) optional, fails gracefully when unavailable
- huggingface-hub version >=0.19.0 for latest cache_dir features

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

requirements.txt

@@ -1,7 +1,21 @@
+# Gradio Framework (version controlled via README.md sdk_version for HF Spaces)
 gradio==5.49.1
+
+# ML Core Libraries
 transformers==4.57.1
 torch==2.9.0
 safetensors==0.6.2
+accelerate==0.26.1
+
+# Tokenizers & Serialization
 sentencepiece==0.2.0
 protobuf==4.25.1
+
+# HF Hub & Authentication
+huggingface-hub>=0.19.0
+
+# Environment Management
 python-dotenv==1.0.0
+
+# ZeroGPU Support (HF Spaces only, graceful fallback on local)
+spaces