Enhance CLI and documentation for capturing VM inventory

- Introduced new `capture` commands in the CLI to allow users to merge VM inventory into local manifests without downloading weights.
- Updated `README.md` and `cli.md` to include detailed instructions for the new capture functionality, including options for models and extensions.
- Enhanced `decisions.md` to clarify the role of captured links in the manifest files.
- Improved `extensions.md` to document the process of capturing installed extensions back to the local configuration.
- Added new functions in `civitai.py` to support fetching model versions by hash and generating canonical URLs for models.

README.md

@@ -59,7 +59,7 @@ Unix: `./gpu-rent.sh …` (один раз `chmod +x gpu-rent.sh`).
 | `tunnel` / `open` | Снова UI / браузер |
 | `hold` / `status` | Пауза killer / состояние |
 | `stop` / `destroy --i-understand-data-loss` | Стоп GPU / + диски |
-| `push` / `pull-output` / `seed-*` | Файлы ↔ VM |
+| `push` / `pull-output` / `seed-*` / `capture` | Файлы ↔ VM; capture = ссылки в yaml |
 
 Полный список: [docs/cli.md](docs/cli.md).