contacts: owners' contacts on their desk phones, copy builtin contacts to Contrack (C6)

Spec 11 §6.2: a phone's directory is the extensions, its owner's own contacts (accepted shares
included), then the company's, in both modes. In Contrack mode, contacts from before Contrack
are offered for copying (contrack.toCopy, POST …/copy-to-contrack: one Contrack bulk import,
skipping what's already there; the builtin rows stay). Tested against a fake and a real
Contrack 2.0.2.

packages/shared/src/contacts.ts

@@ -53,9 +53,18 @@ export type ContactBookDto = {
   items: ContactDto[];
   provider: 'builtin' | 'contrack';
   /** Contrack mode: the address people open, and whether this book's token works. */
-  contrack: { publicUrl: string | null; connected: boolean; error: string | null } | null;
+  contrack: {
+    publicUrl: string | null;
+    connected: boolean;
+    error: string | null;
+    /** Contacts still only in the builtin book (from before Contrack): "Copy them" (11 §5). */
+    toCopy: number;
+  } | null;
 };
 
+/** POST …/contacts/copy-to-contrack (11 §5, C6). */
+export type ContactCopyResult = { added: number; duplicates: number; failed: number };
+
 /** POST …/contacts/import: the files' text, read in the browser. */
 export const ContactImportSchema = z.object({
   files: z