feat(ext/setup): vault-presence probe helper

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

extension/src/setup/__tests__/probe.test.ts

@@ -0,0 +1,49 @@
+import { describe, expect, it, vi } from 'vitest';
+import { probeVault } from '../probe';
+import type { GitHost } from '../../service-worker/git-host';
+
+function fakeHost(opts: {
+  relicarioFiles?: string[];
+  rootFiles?: string[];
+  commit?: { sha: string; author: string; date: string } | null;
+} = {}): GitHost {
+  return {
+    listDir: vi.fn().mockImplementation(async (p: string) => {
+      if (p === '.relicario') return opts.relicarioFiles ?? [];
+      if (p === '') return opts.rootFiles ?? [];
+      return [];
+    }),
+    lastCommit: vi.fn().mockResolvedValue(opts.commit ?? null),
+    readFile: vi.fn(), writeFile: vi.fn(), writeFileCreateOnly: vi.fn(),
+    deleteFile: vi.fn(), putBlob: vi.fn(), getBlob: vi.fn(), deleteBlob: vi.fn(),
+  };
+}
+
+describe('probeVault', () => {
+  it('reports exists=false when repo is empty', async () => {
+    const host = fakeHost();
+    expect(await probeVault(host)).toEqual({ exists: false });
+  });
+
+  it('reports exists=true when manifest.enc is present', async () => {
+    const host = fakeHost({
+      rootFiles: ['manifest.enc', 'README.md'],
+      commit: { sha: 'abc1234', author: 'Alice', date: '2026-04-20T12:00:00Z' },
+    });
+    const result = await probeVault(host);
+    expect(result.exists).toBe(true);
+    expect(result.lastCommit?.author).toBe('Alice');
+  });
+
+  it('reports exists=true when only .relicario/salt is present (partial init)', async () => {
+    const host = fakeHost({ relicarioFiles: ['salt'] });
+    expect((await probeVault(host)).exists).toBe(true);
+  });
+
+  it('omits lastCommit field when API returns null', async () => {
+    const host = fakeHost({ rootFiles: ['manifest.enc'], commit: null });
+    const result = await probeVault(host);
+    expect(result.exists).toBe(true);
+    expect(result.lastCommit).toBeUndefined();
+  });
+});

extension/src/setup/probe.ts

@@ -0,0 +1,23 @@
+import type { GitHost } from '../service-worker/git-host';
+
+export interface VaultProbe {
+  exists: boolean;
+  lastCommit?: { sha: string; author: string; date: string };
+}
+
+/// Detect whether the configured remote already contains a relicario vault.
+/// Considered present if any of: .relicario/salt, .relicario/params.json,
+/// manifest.enc exists. Best-effort metadata fetch via lastCommit().
+export async function probeVault(host: GitHost): Promise<VaultProbe> {
+  const [relicarioFiles, rootFiles] = await Promise.all([
+    host.listDir('.relicario'),
+    host.listDir(''),
+  ]);
+  const exists =
+    relicarioFiles.includes('salt') ||
+    relicarioFiles.includes('params.json') ||
+    rootFiles.includes('manifest.enc');
+  if (!exists) return { exists: false };
+  const lastCommit = await host.lastCommit('manifest.enc');
+  return lastCommit ? { exists, lastCommit } : { exists };
+}