Fix Phase 2: fusion layer processes text-only via learnable residual gate for gradient flow

Fix: register LLM as nn.Module submodule so optimizer finds LoRA params

Add GPU diagnostic script, fix architecture loading with low_cpu_mem_usage and sync

Day 3 COMPLETE: Full model architecture

Day 1 Complete: Tokenizer setup — Qwen2.5-Coder-7B base + 22 MINDI special tokens (vocab 151,685), wrapper class, full format test

feat: initial project scaffold for MINDI 1.5 Vision-Coder