feat: 2026 model refresh + robustness, CPU-efficiency & UI overhaul

fix: add missing meeting_summarizer module to Dockerfile for HF Spaces deployment

Invalidate Docker cache to force fresh app.py copy

Fix runtime error: add libgomp1 for OpenMP support

Use prebuilt llama-cpp-python wheel for faster builds

Exclude transcripts from HF Spaces deployment

Add HuggingFace Spaces demo with Gradio UI