Add distributed settings and workspace import/export (M5)

src/app/stores/SnippetStore.ts

@@ -46,6 +46,13 @@ export interface SnippetState {
 
   /** Replace the library from storage and choose an active snippet. */
   hydrate: (snippets: Snippet[], activeId?: string | null) => void;
+  /**
+   * Append imported snippets (spec §08 → merge: appended, never overwritten). Ids
+   * are assumed already unique against the library (the import service reassigns
+   * collisions). Keeps the current selection; selects the newest import only when
+   * nothing is active, so an import into an empty workspace lands the user on it.
+   */
+  addSnippets: (incoming: Snippet[]) => void;
   /** Create a new snippet (sample template by default), prepend, and select it. */
   createSnippet: (options?: CreateSnippetOptions) => string;
   /** Make a snippet active and load its draft into the editor buffer. */
@@ -148,6 +155,22 @@ export const useSnippetStore = create<SnippetState>((set, get) => ({
     }));
   },
 
+  addSnippets: (incoming) => {
+    if (incoming.length === 0) return;
+    set((s) => {
+      const snippets = [...incoming, ...s.snippets];
+      if (s.activeSnippetId !== null) return { snippets };
+      const id = newestId(snippets);
+      return {
+        snippets,
+        activeSnippetId: id,
+        draftText: draftFor(snippets, id),
+        editorView: 'draft',
+        bufferEpoch: s.bufferEpoch + 1,
+      };
+    });
+  },
+
   createSnippet: (options) => {
     get().commitDraft(); // flush the outgoing snippet's valid edits before switching away
     const created = createSnippet(options);