fix(wx): strip identity from share page_path; guard router unionid switch

- Sanitize page_path before router.push (H5) to prevent cross-user login via shared link
- onShareAppMessage: remove unionid/openid/status and related query keys from shared path
- main.ts: fix login(to.query.toString()) bug; when already logged in, strip foreign unionid from URL instead of logout

Made-with: Cursor

weapp/pages/index/index.js

@@ -211,8 +211,29 @@ Page({
     onShareAppMessage({from, target, webViewUrl}) {
         log.info("share", [from, target, webViewUrl].join(" | "))
         let pathname = webViewUrl.replace(app.globalData.server, '');
-        if (pathname !== '/') {
-          pathname = encodeURIComponent(pathname)
+        // 分享勿带 WebView 入口里的 unionid/openid/status 等，避免接收方串号
+        if (pathname && pathname !== '/') {
+          try {
+            const q = pathname.indexOf('?')
+            let base = pathname
+            let search = ''
+            if (q === 0) {
+              base = '/'
+              search = pathname.slice(1)
+            } else if (q > 0) {
+              base = pathname.slice(0, q) || '/'
+              search = pathname.slice(q + 1)
+            }
+            if (search) {
+              const sp = new URLSearchParams(search)
+              ;['unionid', 'openid', 'status', 'nickName', 'avatarUrl', 'ts', 'scene'].forEach((k) => sp.delete(k))
+              const rest = sp.toString()
+              pathname = rest ? `${base}?${rest}` : (base || '/')
+            }
+          } catch (e) {
+            log.info('share strip query skip', e)
+          }
+          pathname = pathname === '/' ? '/' : encodeURIComponent(pathname)
         }
         const promise = new Promise(resolve => {
           setTimeout(() => {