Feat(cloud): the portable host service can delete a linked vault

2.33.0 added deleteCloudVault to the bridge contract and implemented it
in the desktop service only. The mobile shells build their cloud sync on
the portable CloudSyncHostService in shared-domain, so the contract
change left them without a way to honor the new Delete Cloud vault
button that app-core now shows everywhere.

deleteLinkedVault mirrors the desktop method: the remote DELETE goes
first, and the link is dropped only after it succeeds, so a failed
delete leaves the user able to retry. Local files are never touched.
The SyncClient pick gains deleteVault, which CloudSyncApiClient already
provides.

Claude-Session: https://claude.ai/code/session_01L1yahiA1JRUKBh5mp3xoBP

Author: adibhanna

packages/shared-domain/src/cloud-sync-host-service.test.ts

@@ -69,6 +69,7 @@ function setup(vaults: CloudSyncVault[] = []) {
         updated_at: '2026-08-10T12:00:00.000Z'
       }
     })),
+    deleteVault: vi.fn(async () => undefined),
     manifest: vi.fn(async () => ({ data: [], cursor: 0, next_page: null })),
     changes: vi.fn(async () => ({ data: [], cursor: 0, has_more: false })),
     mutate: vi.fn(async (_vaultId: string, body: CloudSyncMutationRequest) => ({
@@ -206,6 +207,26 @@ describe('CloudSyncHostService', () => {
     expect(hostVault.refresh).toHaveBeenCalledTimes(1)
   })
 
+  it('deletes the remote vault before dropping the link', async () => {
+    const { client, hostVault, service } = setup()
+
+    await service.createAndLink(hostVault, 'My Notes')
+    await service.deleteLinkedVault(hostVault)
+
+    expect(client.deleteVault).toHaveBeenCalledWith('vault-created')
+    await expect(service.linkedVault(hostVault)).resolves.toBeNull()
+  })
+
+  it('keeps the link when the remote delete fails', async () => {
+    const { client, hostVault, service } = setup()
+
+    await service.createAndLink(hostVault, 'My Notes')
+    client.deleteVault.mockRejectedValueOnce(new Error('offline'))
+
+    await expect(service.deleteLinkedVault(hostVault)).rejects.toThrow('offline')
+    await expect(service.linkedVault(hostVault)).resolves.toMatchObject({ vault_id: 'vault-created' })
+  })
+
   it('refuses to sync a link from a different cloud origin', async () => {
     const { hostVault, persistence, service } = setup()
     await persistence.saveLink(hostVault.key, {

packages/shared-domain/src/cloud-sync-host-service.ts

@@ -25,6 +25,7 @@ type SyncClient = Pick<
   | 'account'
   | 'listVaults'
   | 'createVault'
+  | 'deleteVault'
   | 'manifest'
   | 'changes'
   | 'mutate'
@@ -120,6 +121,18 @@ export class CloudSyncHostService {
     await this.dependencies.persistence.deleteLink(vault.key)
   }
 
+  /**
+   * Delete the cloud copy this vault is linked to, then drop the link.
+   * Mirrors the desktop service: the remote call goes first so a failure
+   * leaves the link (and the user's ability to retry) intact. Local files are
+   * never touched.
+   */
+  async deleteLinkedVault(vault: CloudSyncHostVault): Promise<void> {
+    const { client, link } = await this.linkedConnection(vault)
+    await client.deleteVault(link.vault_id)
+    await this.unlink(vault)
+  }
+
   async listBackups(vault: CloudSyncHostVault): Promise<CloudBackupSnapshot[]> {
     const { client, link } = await this.linkedConnection(vault)
     return (await client.listBackups(link.vault_id)).data