[diffusion] feat: support single-file component weight overrides (#35979)

docs/docs/sglang-diffusion/api/cli.mdx

@@ -150,6 +150,9 @@ for the current component matrix.
 
 Component overrides accept a local component directory, a standalone Hub
 repository, or a Hub component subfolder written as `owner/repo/subfolder`.
+For transformer and native encoder loaders, an explicit weight filename keeps
+the base component configuration and replaces only its weights; the selected
+file format must still be supported by that loader.
 
 For supported realtime causal video models, `--kv-cache-quant {off|int4|int2}`
 compresses completed KV-cache chunks independently of transformer weight

docs/docs/sglang-diffusion/quantization.mdx

@@ -16,7 +16,7 @@ precision are resolved independently.
 Use these paths:
 
 - `--model-path`: the base or original model
-- `--component-paths.<component>` / `--<component>-path`: replace a component from `model_index.json` or a native registered module with an independent repo or local directory
+- `--component-paths.<component>` / `--<component>-path`: replace a component from `model_index.json` or a native registered module with an independent repo/local directory; for transformer and native encoder loaders, an explicit weight filename retains the base component config
 - `--transformer-path`: a quantized transformers-style transformer component directory that already contains its own `config.json`
 - `--transformer-weights-path`: replacement transformer weights in safetensors
   format (file, directory, or Hub repository/file) or a supported GGUF file