[pratikgx]

Fixes links in the docs that either 404 on GitHub or point to repos that have moved.

Relative links that don't resolve:

• docs/sana_lora_dreambooth.md: ../../train_scripts/train_lora.sh -> ../train_scripts/train_lora.sh
• docs/metrics_toolkit.md: ../model_paths.txt -> ../asset/model_paths.txt
• docs/inference_scaling/inference_scaling.md: ../../../tools/metrics/geneval/geneval_env.md -> ../../tools/metrics/geneval/geneval_env.md
• asset/docs/sana_wm.md: sana-wm-bench.md -> ../../docs/sana-wm-bench.md. The benchmark guide only exists under docs/.

SGLang docs moved (docs/sglang.md):

• sglang/tree/main/docs/diffusion/installation.md -> sglang/blob/main/docs/docs/sglang-diffusion/installation.mdx
• sglang/tree/main/docs/diffusion -> sglang/tree/main/docs/docs/sglang-diffusion

Nunchaku and DeepCompressor moved from mit-han-lab to nunchux-ai. The GitHub API reports the new location.

• The SanaPAG example examples/sana_1600m_pag.py no longer exists. The same example is now examples/sana1.6b_pag.py, which uses SanaPAGPipeline with the Sana 1600M weights. This is updated in docs/model_zoo.md, docs/4bit_sana.md and their asset/docs/ copies.
• The remaining mit-han-lab/nunchaku and mit-han-lab/deepcompressor links now use nunchux-ai/..., and the app/sana/t2i and examples/diffusion paths still exist there.

Not changed:

• docs/8bit_sana.md (and its asset/docs/ copy): the links to ../../using-diffusers/... look copied from the diffusers docs site.
• docs/sana_video.md: the ../sana_video_inference/ link uses the built-site URL style.

Docs only. Every changed link now points to an existing file or folder.