feat(mobile-h5): add local follow-confirm helpers for WeChat notify steps

Co-authored-by: Cursor <cursoragent@cursor.com>

mobile-h5/utils/mp-follow-confirm.js

@@ -0,0 +1,34 @@
+// mobile-h5/utils/mp-follow-confirm.js
+export function followStorageKey(userId) {
+  const id = String(userId || '').trim() || 'anonymous'
+  return 'mp_follow_confirmed:' + id
+}
+
+export function isFollowConfirmed(userId, storage) {
+  const s = storage || (typeof uni !== 'undefined' ? uni : null)
+  if (!s || typeof s.getStorageSync !== 'function') return false
+  try {
+    return String(s.getStorageSync(followStorageKey(userId)) || '') === '1'
+  } catch (_) {
+    return false
+  }
+}
+
+export function setFollowConfirmed(userId, confirmed, storage) {
+  const s = storage || (typeof uni !== 'undefined' ? uni : null)
+  if (!s || typeof s.setStorageSync !== 'function') return
+  try {
+    s.setStorageSync(followStorageKey(userId), confirmed ? '1' : '0')
+  } catch (_) {
+    /* ignore */
+  }
+}
+
+/** @returns {{ step1Done: boolean, step2Done: boolean }} */
+export function resolveStepDone({ bound, followConfirmed }) {
+  if (bound) return { step1Done: true, step2Done: true }
+  return {
+    step1Done: !!followConfirmed,
+    step2Done: false
+  }
+}

mobile-h5/utils/mp-follow-confirm.test.js

@@ -0,0 +1,38 @@
+// mobile-h5/utils/mp-follow-confirm.test.js
+import assert from 'node:assert/strict'
+import {
+  followStorageKey,
+  isFollowConfirmed,
+  setFollowConfirmed,
+  resolveStepDone
+} from './mp-follow-confirm.js'
+
+assert.equal(followStorageKey('u1'), 'mp_follow_confirmed:u1')
+assert.equal(followStorageKey(''), 'mp_follow_confirmed:anonymous')
+
+const store = new Map()
+const api = {
+  getStorageSync: (k) => store.get(k),
+  setStorageSync: (k, v) => {
+    store.set(k, v)
+  }
+}
+assert.equal(isFollowConfirmed('u1', api), false)
+setFollowConfirmed('u1', true, api)
+assert.equal(isFollowConfirmed('u1', api), true)
+assert.equal(isFollowConfirmed('u2', api), false)
+
+assert.deepEqual(resolveStepDone({ bound: true, followConfirmed: false }), {
+  step1Done: true,
+  step2Done: true
+})
+assert.deepEqual(resolveStepDone({ bound: false, followConfirmed: true }), {
+  step1Done: true,
+  step2Done: false
+})
+assert.deepEqual(resolveStepDone({ bound: false, followConfirmed: false }), {
+  step1Done: false,
+  step2Done: false
+})
+
+console.log('mp-follow-confirm: ok')