ui: update title and description

- Remove 'ZeroGPU Optimized' label.
- Rename to 'NeAR — Image-to-Relightable 3D Gaussian Splatting'.
- Update workflow description to match the 4-step split (①②③④).
- Clean up module docstring.

app.py

@@ -1,21 +1,11 @@
 """
-NeAR Gradio Space — ZeroGPU-compatible pipeline (REFACTORED).
+NeAR — Image-to-Relightable 3D Gaussian Splatting
 
-ZeroGPU contract: every @spaces.GPU call gets a **fresh** CUDA context.
-Any CUDA-backed object (nvdiffrast renderer, tone_mapper) from a previous
-call is invalid in the next call.
+Pipeline:
+  ① Geometry  →  ② SLaT  →  ③ Videos  →  ④ PBR GLB
 
-REFACTORED ARCHITECTURE:
-- ① Generate Geometry (Hunyuan3D) — independent GPU callback
-- ② Generate SLaT (NeAR) — independent GPU callback  
-- ③④ MERGED: Generate Videos + Export PBR GLB — SINGLE GPU callback
-  * Avoids cross-callback CUDA context resets
-  * Renderer/tone_mapper stay valid throughout rendering and export
-
-Session state = file paths only. No in-memory objects retained between
-steps (except within the unified ③④ callback).
-
-CPU preload runs in a background daemon thread at Space startup (no GPU lease).
+- ZeroGPU: each @spaces.GPU callback gets a fresh CUDA context.
+- CPU preload: Hunyuan3D + NeAR weights warmed at container start.
 """
 from __future__ import annotations
 
@@ -802,15 +792,16 @@ def build_app() -> gr.Blocks:
     import warnings
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", UserWarning)
-        _blocks_ctx = gr.Blocks(title="NeAR — Relightable 3D", theme=THEME, css=CSS, fill_width=True)
+        _blocks_ctx = gr.Blocks(title="NeAR — Relightable 3DGS", theme=THEME, css=CSS, fill_width=True)
     with _blocks_ctx as demo:
         asset_state = gr.State({})
 
         gr.Markdown(
-            "## NeAR — Relightable 3D (ZeroGPU Optimized)\n"
-            "**① Geometry** → **② SLaT** → **③④ Videos + PBR GLB** (merged for stability)\n\n"
-            "Tip: after generating geometry, swap the input image before running **② SLaT** "
-            "to apply a different texture style to the same shape — geometry and appearance are decoupled."
+            "## NeAR — Image-to-Relightable 3D Gaussian Splatting\n"
+            "**① Geometry** → **② SLaT** → **③ Videos** → **④ PBR GLB**\n\n"
+            "Upload an image and walk through the four steps.  "
+            "Geometry and appearance are decoupled — after step ① you can swap the input image "
+            "before step ② to retexture the same mesh with a different style."
         )
 
         with gr.Row(equal_height=False):