UNIPOS REPORTS LOGIN UPDATE

Super Admin: /pos_reports/admin.php
Shop Admin and viewers: /pos_reports/shop_login.php
Shop management: /pos_reports/shop_admin.php (requires Shop Admin role)
Reports: /pos_reports/index.php

Shop login now selects the shop explicitly. Existing usernames and password hashes remain unchanged.
Both Super Admin and Shop Admin can use username admin. Different shops may reuse usernames.

DEPLOYMENT:
1. Back up the entire existing pos_reports directory.
2. Upload only the PHP files from this patch ZIP into /pos_reports/ (overwrite matching PHP files).
3. Do NOT upload/overwrite accounts.json, config.php, private/ or LIVE_POS.PRG.
4. Sign out, open /pos_reports/shop_login.php, select shoppy and use its existing Shop Admin username and password.
5. Super Admin continues to use /pos_reports/admin.php.

If you are signed in as Super Admin, the shop login can switch to a shop account after successful password verification.
