Toppings (Delta + LoRA support)

[xzyaoi]

Stage 1 (in PR #10):

• System Controller for Topping Registration
• Toppings Manager (Detects, Loads, Swap toppings)
• Kernels (Delta + LoRA kernel @enothum)
• Statistics Logger

Stage 2:

• FP16 full swap support
• Correctness verification
• Improved stats logger

Step 3:

• Tensor Parallelism support