FUEL STATION MANAGEMENT SYSTEM - V2 CHANGES

1. ROLE / PRIVILEGE CONTROL
- Super Admin: can work with one selected station context at a time and has full system access.
- Admin: Station Admin; limited to the assigned station. Can manage station users, reset passwords, sales, expenses and station operations. Cannot create stations or access other stations.
- Manager: assigned-station access. Can record sales only against an open shift, manage expenses, shifts and own settings. Cannot manage users or station configuration.
- Cashier: assigned-station access. Can record sales only against an open shift, see own dashboard sales/litres/transactions and print own daily sales report. No profit figures and no management modules.

2. SUPER ADMIN STATION CONTEXT
- Super Admin selects a station from the Dashboard top bar.
- Active station is stored in session and shown as a station badge.
- Station operations are scoped to the selected station to reduce accidental data mixing.

3. SHIFT / METER CONNECTION
- New table: shift_meter_readings.
- Opening meter is snapshotted for every active nozzle when a shift opens.
- Current meter is increased by recorded sale litres.
- Closing meter is entered when a shift closes.
- Dispensed = Closing Meter - Opening Meter.
- fuel_nozzles.current_meter is updated when a sale is recorded and when a shift closes.
- The next shift starts from the latest nozzle current meter.
- Sales require an open shift belonging to the active station and are linked using fuel_sales.shift_id.

4. CASHIER REPORT
- Added fuel/reports/cashier.php.
- Shows the logged-in cashier's transactions, litres and sales amount for a selected day.
- Profit information is intentionally excluded.
- Browser print is available.

5. EXPENSE CATEGORIES
The expense type is now a dropdown with:
- Logistics
- Office Facilities
- Maintenance and Repair
- Salary and Allowances
- Foods and Drinks
- Rent
- Electricity
- Internet Bundle
- Other

6. USER MANAGEMENT
- Super Admin can manage all users.
- Station Admin can manage users belonging to the assigned station.
- Station Admin can create only Manager and Cashier accounts.
- Password reset/edit is available for authorized station users.
- Users page displays the actual role stored for every account.

7. NAVIGATION / SAFETY
- Protected pages send no-cache headers to reduce stale browser-back data.
- Invalid local navigation links in the supplied project were corrected where identified.
- Legacy /employees/ route now redirects to /fuel/employees/.

8. DATABASE MIGRATION
Run:
 database/migration_v2_roles_meter.sql

IMPORTANT:
- Make a database backup before running the migration.
- The migration creates shift_meter_readings and adds an index to fuel_sales.shift_id if missing.
- Existing historical shifts do not have opening meter snapshots if the old system never stored them. New shifts will store them correctly.
