chore: durcit la configuration pour la production

- mobile: externalise l'URL d'API via EXPO_PUBLIC_API_URL (repli localhost en dev)
- backend: .env.example adapté au projet (PostgreSQL, JWT, FRONTEND_URL, Redis)
- frontend/mobile: ajoute .env.example (+ exception gitignore front)
- mobile: supprime les 4 `any` (helper getApiError, type Feed, glyphMap Ionicons)
- backend: normalise le style PSR-12 via Pint (13 fichiers)

Tests backend 15/15, mobile tsc 0, Pint pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/bootstrap/app.php

@@ -1,5 +1,8 @@
 <?php
 
+use App\Http\Middleware\ForceJsonResponse;
+use App\Http\Middleware\JwtMiddleware;
+use App\Http\Middleware\RoleMiddleware;
 use Illuminate\Foundation\Application;
 use Illuminate\Foundation\Configuration\Exceptions;
 use Illuminate\Foundation\Configuration\Middleware;
@@ -13,12 +16,12 @@ return Application::configure(basePath: dirname(__DIR__))
     )
     ->withMiddleware(function (Middleware $middleware): void {
         $middleware->alias([
-            'jwt.auth' => \App\Http\Middleware\JwtMiddleware::class,
-            'role' => \App\Http\Middleware\RoleMiddleware::class,
+            'jwt.auth' => JwtMiddleware::class,
+            'role' => RoleMiddleware::class,
         ]);
 
         $middleware->api(prepend: [
-            \App\Http\Middleware\ForceJsonResponse::class,
+            ForceJsonResponse::class,
         ]);
     })
     ->withExceptions(function (Exceptions $exceptions): void {