Oasis 0.9.5 con Karvan para escritorio

Rama de desarrollo experimental sobre el Oasis de epsylon, sin afiliacion con el
proyecto original. Base: 0.9.5.

Trae el modulo Karvan —salas efimeras en memoria con autodestruccion por TTL, chat
que funciona sin JavaScript y llamadas de audio y video sobre WebRTC— con el enlace
en el menu lateral por el mismo patron que el resto de modulos: renderKarvanLink
calcado de renderPollsLink, entrada en modules_view y en la lista de /modules.

Los estilos del modulo van en su propia hoja, styles/karvan.css, siguiendo el patron
de highlight.css: asi se ve igual con cualquier tema, sin depender del tema movil.

Sin servidores ICE de terceros: no hay STUN de fabrica, porque un STUN aprende la IP
publica y el momento de cada llamada. Solo candidatos host salvo que se configure un
TURN propio en oasis-config.json, con credenciales efimeras por el mecanismo REST de
coturn.

El codigo propio vive separado —views/fork/, backend/fork_routes.js,
models/karvan_model.js y translations/fork/— de modo que sobre los ficheros de
upstream solo hay enganches de una linea y cada version nueva se integra sin
arrastrar nada.

Respecto al arbol de Android: fuera el wrapper y main.js, que es su arranque; el
tema vuelve a Dark-SNH y se restauran los modulos que en movil se recortan por peso.

Verificado arrancando sin OASIS_MOBILE: nueve rutas OK, menu lateral de upstream con
27 grupos y el enlace de Karvan, cero rastro de la interfaz movil (ni hexagonos, ni
topbar, ni barra inferior), y una sala creada y servida.

docs/devs/contributing.md

@@ -0,0 +1,68 @@
+# Contributing
+
+If you want to dive into the details, please see the [contract](./contract.md)
+that defines the contributor role in this project. If you're comfortable with
+a top-level summary, you can start here first.
+
+Our workflow is basically [GitHub Flow][github-flow] with specific roles:
+
+- **Contributor:** Write patches that reduce the number of problems.
+- **Maintainers:** Merge patches that reduce the number of problems.
+
+If you have an issue, it's best to open an issue to describe the problem and
+discuss solutions, but don't worry if you've already skipped that step.
+
+Assuming you already have a [developer install](./install.md) you should be
+able to start editing source code. There are a few useful commands you should
+know about:
+
+- **`npm install`**: Ensure that software dependencies are installed.
+- **`npm test`**: Ensure that all automated tests pass.
+- **`npm run fix`**: If an automated test failed, this may fix it.
+
+Please run `npm test` before writing a commit, because if there are errors then
+maintainers won't be able to merge your patch. Please ask for help if `npm test`
+is giving you any trouble.
+
+**Note:** `npm run fix` is run automatically as a pre-commit hook. You always
+have the option to disable pre-commit hooks with `git commit --no-verify`.
+
+## Frequently Failed Tests
+
+### Unknown word
+
+<!-- spell-checker:disable -->
+
+```
+/src/index.js:10:42 - Unknown word (Scuttlebtut)
+```
+
+<!-- spell-checker:enable -->
+
+If this word is a typo, please fix the typo. If this error is a mistake, and
+you're sure that this is a word, please add the word to `.cspell.json`.
+
+### Code style issues found
+
+```
+Checking formatting...
+src/index.js
+README.md
+Code style issues found in the above file(s). Forgot to run Prettier?
+```
+
+You can use `npm run fix` to resolve inconsistent code style. Please remember to
+add those changes with `git add` or similar before you commit.
+
+## Tips
+
+### TypeScript opportunities
+
+If you're looking for places where TypeScript would enjoy more detail, you can
+run the TypeScript linter with `--noImplicitAny`:
+
+```sh
+npx tsc --allowJs --resolveJsonModule --lib es2018,dom --checkJs --noEmit --skipLibCheck --noImplicitAny src/index.js
+```
+
+[github-flow]: https://guides.github.com/introduction/flow/