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/app/Http/Controllers/SaisieTrackerController.php

@@ -3,7 +3,6 @@
 namespace App\Http\Controllers;
 
 use App\Http\Requests\StoreSaisieRequest;
-use App\Models\SaisieTracker;
 use App\Services\RapportService;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
@@ -14,7 +13,7 @@ class SaisieTrackerController extends Controller
     {
         $tracker = auth()->user()->tracker;
 
-        if (!$tracker) {
+        if (! $tracker) {
             return response()->json([]);
         }
 
@@ -39,7 +38,7 @@ class SaisieTrackerController extends Controller
     {
         $tracker = auth()->user()->tracker;
 
-        if (!$tracker) {
+        if (! $tracker) {
             $tracker = auth()->user()->tracker()->create(['nom' => 'Mon journal']);
         }