docs: update README and forge documentation

- README: Fixed backend command, added GPU compatibility reference
- forge.md: Fixed train CLI (--output-dir), added GPU troubleshooting
- Added reference to GPU compatibility guide for RTX 50-series

README.md

@@ -39,6 +39,7 @@ A fully local, privacy-first AI companion trained on your Obsidian vault. Combin
 - Node.js 18+ (for UI)
 - Ollama running locally
 - RTX 5070 or equivalent (12GB+ VRAM for fine-tuning)
+- See [GPU Compatibility Guide](docs/gpu-compatibility.md) for RTX 50-series setup
 
 ### Installation
 
@@ -76,7 +77,7 @@ See [docs/config.md](docs/config.md) for full configuration reference.
 
 **Terminal 1 - Backend:**
 ```bash
-python -m uvicorn companion.api:app --host 0.0.0.0 --port 7373
+python -m companion.api
 ```
 
 **Terminal 2 - Frontend:**
@@ -139,8 +140,9 @@ python -m companion.forge.cli reload ~/.companion/training/final
 | `companion.config` | Configuration management | [docs/config.md](docs/config.md) |
 | `companion.rag` | RAG engine (chunk, embed, search) | [docs/rag.md](docs/rag.md) |
 | `companion.forge` | Fine-tuning pipeline | [docs/forge.md](docs/forge.md) |
-| `companion.api` | FastAPI backend | [docs/api.md](docs/api.md) |
+| `companion.api` | FastAPI backend | This README |
 | `ui/` | React frontend | [docs/ui.md](docs/ui.md) |
+| **GPU Setup** | RTX 50-series compatibility | [docs/gpu-compatibility.md](docs/gpu-compatibility.md) |
 
 ## Project Structure