Feature Request: Add Normalized Attention Guidance (NAG) and Token Perturbation Guidance (TPG) as built-in extensions

### Description

It would be great to integrate two recent guidance methods directly into Forge:

* **TPG (Token Perturbation Guidance)** – [[Paper](https://arxiv.org/abs/2506.10036)](https://arxiv.org/abs/2506.10036) | [[Code](https://github.com/TaatiTeam/Token-Perturbation-Guidance)](https://github.com/TaatiTeam/Token-Perturbation-Guidance)
* **NAG (Normalized Attention Guidance)** – [[Paper](https://arxiv.org/abs/2505.21179)](https://arxiv.org/abs/2505.21179) | [[Code](https://github.com/ChenDarYen/Normalized-Attention-Guidance)](https://github.com/ChenDarYen/Normalized-Attention-Guidance)

**Why?**

* Complements existing built-in guidances (SAG, PAG).
* Improves prompt adherence (TPG) and stability/semantic faithfulness (NAG).
* Already tested in the community: see [[sd-perturbed-attention extension](https://github.com/pamparamm/sd-perturbed-attention)](https://github.com/pamparamm/sd-perturbed-attention) and [[this PR for NAG](https://github.com/pamparamm/sd-perturbed-attention/pull/44)](https://github.com/pamparamm/sd-perturbed-attention/pull/44).

No Forge files or tests are named. Start by reviewing the linked TPG and NAG implementations, then compare them with Forge's existing SAG and PAG guidances to identify integration points. Done means both methods are available as built-in Forge guidances.

Written by the indexing model from the issue text.