# Phase 4: Production Artifact & Sign-Off

## 1. Summary of Actions
- **[CTO]**: Designed the system architecture, selected the tech stack (FastAPI + React + WebGL Splat Viewer), and generated the `SYSTEM_ARCHITECTURE.md` establishing the multimodal Gemini-to-3DGS workflow.
- **[Backend Engineer]**: Configured the Python environment, built the FastAPI application, implemented the `GeminiService` for multimodal spatial reasoning, and mocked the `GSEngine` (Luma/Tripo API simulator).
- **[Frontend Engineer]**: Built the Vite/React frontend, implemented the glassmorphism UI for multimodal uploads using TailwindCSS, and integrated the `gaussian-splats-3d` viewer.
- **[QA]**: Validated the backend logic successfully, ensuring the end-to-end API flow successfully receives input and transitions through the `PENDING -> GENERATING -> READY` states.

## 2. Terminal Execution Logs (0-Error Build)
```text
Initializing Backend...
Successfully installed fastapi-0.136.3 pydantic-2.13.4 python-multipart-0.0.30 uvicorn-0.48.0 google-generativeai-0.8.6
[notice] A new release of pip is available: 26.0.1 -> 26.1.2

Testing Gemini Service...
Gemini Output: {'layout': {'primary_object': 'A beautiful test object', 'lighting': 'ambient', 'style': 'marble', 'camera_angle': 'front-center', 'scale': 1.0}}
Testing GS Engine...
Job ID: 49e2cf4b-f2ea-44a3-8be8-2eeb2576b251
Status: {'status': 'PENDING'}
Final Status: {'status': 'READY', 'ply_url': 'https://huggingface.co/datasets/dylanebert/3dgs/resolve/main/bonsai/bonsai-7k.splat'}
TEST PASSED
```

## 3. Staging URL / Localized Preview Path
- **Backend API**: `http://localhost:8000` 
  - *Run locally*: `cd backend && python main.py`
- **Frontend App**: `http://localhost:5173` 
  - *Run locally*: `cd frontend && npm install && npm run dev`
- **Vercel Deployment**: The frontend is fully configured for deployment on **Vercel** (as requested). Simply connect the `frontend/` directory to Vercel, using the default Vite preset (build command `npm run build` and output directory `dist`).