feat(shared): lift recovery-code primitives into shared crypto module

packages/shared/src/crypto/recoveryCode.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it, beforeAll } from 'vitest';
+
+import { setCryptoBackend } from './backend';
+import { makeWasmTestBackend } from './testBackend';
+import { generateRecoveryCode, normalizeRecoveryCode, RECOVERY_CODE_LEN } from './recoveryCode';
+
+beforeAll(async () => { setCryptoBackend(await makeWasmTestBackend()); });
+
+describe('recoveryCode', () => {
+  it('generates a 24-char alphabet-restricted code grouped 4×6 with dashes', async () => {
+    const code = await generateRecoveryCode();
+    expect(code).toHaveLength(27);
+    const groups = code.split('-');
+    expect(groups).toHaveLength(4);
+    for (const g of groups) expect(g).toMatch(/^[ABCDEFGHJKLMNPQRSTUVWXYZ23456789]{6}$/);
+  });
+
+  it('normalizeRecoveryCode strips dashes/spaces and uppercases', () => {
+    expect(normalizeRecoveryCode(' abcdef-ghjklm-npqrst-uvwxyz ')).toBe('ABCDEFGHJKLMNPQRSTUVWXYZ');
+  });
+
+  it('normalizeRecoveryCode drops characters outside the alphabet', () => {
+    expect(normalizeRecoveryCode('AB1OD-EF0H1J')).toBe('ABDEFHJ');
+  });
+
+  it('RECOVERY_CODE_LEN matches alphabet length', () => {
+    expect(RECOVERY_CODE_LEN).toBe(24);
+  });
+});