fix(api-url): todas las apps usan || en vez de ?? para VITE_API_URL

- 11 archivos corregidos: agente-ia, alta-clientes, cobranza, cotizador,
  dashboards, mi-dia, landing (auth.ts, api.ts, mi-dia.ts, reportes.ts,
  push.ts, notas.ts, recordatorios.ts, reporte-mi-tablero.ts)
- ?? solo cubre null/undefined, || cubre string vacío
- 7 apps reconstruidas

apps/mi-dia/src/services/mi-dia.ts

@@ -2,7 +2,7 @@
 import type { ResumenMiDia } from '../lib/mi-dia'
 import { conAuth, manejar401 } from './auth'
 
-const API_URL = import.meta.env.VITE_API_URL ?? '/api'
+const API_URL = import.meta.env.VITE_API_URL || '/api'
 
 async function fetchJson<T>(path: string, init: RequestInit = {}): Promise<T> {
   const res = await fetch(`${API_URL}${path}`, conAuth(init))

apps/mi-dia/src/services/notas.ts

@@ -1,6 +1,6 @@
 import { conAuth, manejar401 } from './auth'
 
-const API_URL = import.meta.env.VITE_API_URL ?? '/api'
+const API_URL = import.meta.env.VITE_API_URL || '/api'
 
 export interface NotaApartado {
   id: string

apps/mi-dia/src/services/push.ts

@@ -1,6 +1,6 @@
 import { conAuth, manejar401 } from './auth'
 
-const API_URL = import.meta.env.VITE_API_URL ?? '/api'
+const API_URL = import.meta.env.VITE_API_URL || '/api'
 
 /** Convierte la VAPID public key (base64url) a Uint8Array para PushManager */
 function urlBase64ToUint8Array(base64String: string): Uint8Array {

apps/mi-dia/src/services/recordatorios.ts

@@ -1,6 +1,6 @@
 import { conAuth, manejar401 } from './auth'
 
-const API_URL = import.meta.env.VITE_API_URL ?? '/api'
+const API_URL = import.meta.env.VITE_API_URL || '/api'
 
 export interface Recordatorio {
   id: string

apps/mi-dia/src/services/reporte-mi-tablero.ts

@@ -1,6 +1,6 @@
 import { conAuth, manejar401 } from './auth'
 
-const API_URL = import.meta.env.VITE_API_URL ?? '/api'
+const API_URL = import.meta.env.VITE_API_URL || '/api'
 
 async function fetchJson<T>(path: string, init: RequestInit = {}): Promise<T> {
   const res = await fetch(`${API_URL}${path}`, conAuth(init))