release: IDE multi-projet + app native (git-arboretum 3.0.0, vscode 0.3.0, desktop 0.1.0)

Daemon 3.0.0 : marque le cap « IDE IA multi-projet + app de bureau native » (refonte additive, PROTOCOL_VERSION inchangé ; le tarball embarque la nouvelle SPA IDE + le handshake token desktop). Extension VS Code 0.3.0 : deep-link « Open Worktree IDE » vers l'IDE multi-projet, encodage wt-key unifié via @arboretum/shared (CHANGELOG + README à jour). Paquet desktop 0.1.0 (première release).

package.json ET package-lock.json bumpés (npm ci strict). 431 tests, 0 tiret, builds daemon/web/vscode/site verts.

packages/vscode/README.md

@@ -11,9 +11,9 @@ integration on top of the [Arboretum](https://git.lidge.fr/johanleroy/arboretum)
   input: answer **Yes/No** without even opening the terminal (uses the daemon's `answer` command).
 - **Git mutations** from the tree: create worktree, commit, push, fetch, pull, promote to main, with a
   **detailed git status** on each worktree (staged / unstaged / conflicts and the last commit subject).
-- **Open Worktree IDE**: jump from any worktree to its full `/workspace` view (file tree, Monaco editor,
-  inline diffs, integrated terminal) in the browser. The extension stays a lightweight visual worktree
-  manager: the heavy editing lives in the web IDE.
+- **Open Worktree IDE**: jump from any worktree into the multi-project IDE (unified project / worktree /
+  session tree, tabbed Monaco editor with inline diffs, docked terminals), in the browser or the native
+  desktop app. The extension stays a lightweight visual worktree manager: the heavy editing lives in the IDE.
 - **Workspace-aware**: the worktree matching your open folder is highlighted; start a session or create a
   worktree for the current folder in one command.