0.10.5: icon-only Sync button that keeps its size and colour

On a diagram page it goes last in Archify's toolbar, after Export, instead
of floating over it. Every rule is !important and flex: none, so the page's
button styles, narrow windows and high contrast themes no longer squeeze it
or strip its colour.

README.md

@@ -140,7 +140,7 @@ Optional. Without a sync server the extension works exactly as described above a
 
 [Archify Sync](https://gitea.lego-cloud.eu/vscode-extensions/archify-vscode-ext-sync) is a small server you run yourself (one container and PostgreSQL; a Helm chart is included). With it, a model is edited by several people at once, like a shared document, and its files stay ordinary files on each person's disk, so Git, agents and every page of this extension keep working.
 
-- **Where.** Every Archify page (diagram, model, graph, registry, decision, also in Source) has a **Sync** button top right. It opens the Sync menu: sign in, share the model, join one, the server address, settings. On a shared model it turns green and reads **Shared**. The same menu is *Archify | Sync…* in the Command Palette.
+- **Where.** Every Archify page (diagram, model, graph, registry, decision, also in Source) has a Sync button (a cloud) top right; on a diagram it sits after **Export**. It opens the Sync menu: sign in, share the model, join one, the server address, settings. On a shared model it turns green with a broadcast icon. The same menu is *Archify | Sync…* in the Command Palette.
 - **Server address.** Set `archify.sync.server` once (Settings › Archify › Sync, or *Archify | Set Sync Server Address…*), for example `https://archify.example.com`. Put it in the workspace settings and everyone in the project uses the same server. Left empty, the address is asked for once and remembered.
 - **Sign in.** *Archify | Sign in to Sync Server…* uses that address (or asks for it) and signs in through the browser; the session is kept in VS Code's secret storage and shows under **Accounts** as *Archify Sync*. A new server is set up first on its `/setup` page with the code from its log.
 - **Share.** *Archify | Share Model…* (also on `main.archify` in the Explorer) puts the model on the server and writes a small `.archify-sync` file next to `main.archify`: the server and the model's id, no secrets. Commit it, and everyone who clones the repository and is a member opens the shared model.