Add 3-level role permissions, organismos operadores, and Histórico de Tomas page

Implements the full ADMIN → ORGANISMO_OPERADOR → OPERATOR permission hierarchy
with scope-filtered data access across all backend services. Adds organismos
operadores management (ADMIN only) and a new Histórico page for viewing
per-meter reading history with chart, consumption stats, and CSV export.

Key changes:
- Backend: 3-level scope filtering on all services (meters, readings, projects, users)
- Backend: Protect GET /meters routes with authenticateToken for role-based filtering
- Backend: Pass requestingUser to reading service for scoped meter readings
- Frontend: New HistoricoPage with meter selector, AreaChart, paginated table
- Frontend: Consumption cards (Actual, Pasado, Diferencial) above date filters
- Frontend: Meter search by name, serial, location, CESPT account, cadastral key
- Frontend: OrganismosPage, updated Sidebar with 3-level visibility
- SQL migrations for organismos_operadores table and FK columns

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

water-api/sql/add_user_meter_fields.sql

@@ -0,0 +1,11 @@
+-- Add new fields to users table
+ALTER TABLE users ADD COLUMN IF NOT EXISTS phone VARCHAR(20);
+ALTER TABLE users ADD COLUMN IF NOT EXISTS street VARCHAR(255);
+ALTER TABLE users ADD COLUMN IF NOT EXISTS city VARCHAR(100);
+ALTER TABLE users ADD COLUMN IF NOT EXISTS state VARCHAR(100);
+ALTER TABLE users ADD COLUMN IF NOT EXISTS zip_code VARCHAR(10);
+
+-- Add new fields to meters table
+ALTER TABLE meters ADD COLUMN IF NOT EXISTS address TEXT;
+ALTER TABLE meters ADD COLUMN IF NOT EXISTS cespt_account VARCHAR(50);
+ALTER TABLE meters ADD COLUMN IF NOT EXISTS cadastral_key VARCHAR(50);