feat: phase A — backup B2, healthcheck /api/status, vector tiles Tippecanoe

- A1: scripts/backup-postgres.sh — pg_dump quotidien compressé → Backblaze B2 (rclone), rétention 30j
- A2: StatusController retourne HTTP 503 + healthy/alertReason si dernière observation > 6h
- A4: Dockerfile installe tippecanoe, GenerateTilesCommand génère 5 tilesets (obs + h6/12/24/48), Caddyfile sert /tiles/* sans fallback SPA, SargassesMap.jsx passe en sources vector tiles statiques
- chore: backend/public/assets/ ajouté au .gitignore (build artifacts)
- chore: setup vitest frontend + ImpactScoreServiceTest (session précédente)

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

backend/src/Command/GenerateTilesCommand.php

@@ -0,0 +1,151 @@
+<?php
+
+namespace App\Command;
+
+use Doctrine\DBAL\Connection;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+use Symfony\Component\DependencyInjection\Attribute\Autowire;
+
+#[AsCommand(
+    name: 'app:generate-tiles',
+    description: 'Génère les vector tiles (Tippecanoe) pour observations et prédictions',
+)]
+class GenerateTilesCommand extends Command
+{
+    private const TILE_HORIZONS = [6, 12, 24, 48];
+    private const MIN_ZOOM      = 5;
+    private const MAX_ZOOM      = 12;
+
+    public function __construct(
+        private Connection $connection,
+        #[Autowire('%kernel.project_dir%')] private string $projectDir,
+        private LoggerInterface $logger,
+    ) {
+        parent::__construct();
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        $io->title('Génération vector tiles');
+
+        $tilesDir = $this->projectDir . '/public/tiles';
+
+        // Observations
+        $io->section('Observations');
+        $geojson = $this->queryObservationsGeoJSON();
+        if ($geojson !== null) {
+            $this->runTippecanoe($geojson, $tilesDir . '/observations', 'observations', $io);
+        } else {
+            $io->warning('Aucune observation récente — tiles non générées.');
+        }
+
+        // Prévisions par horizon
+        foreach (self::TILE_HORIZONS as $horizon) {
+            $io->section("Prévisions H+{$horizon}");
+            $geojson = $this->queryForecastsGeoJSON($horizon);
+            if ($geojson !== null) {
+                $this->runTippecanoe($geojson, $tilesDir . '/forecasts/h' . $horizon, 'forecasts', $io);
+            } else {
+                $io->warning("Aucune prévision H+{$horizon} — tiles non générées.");
+            }
+        }
+
+        $io->success('Génération terminée.');
+        return Command::SUCCESS;
+    }
+
+    private function queryObservationsGeoJSON(): ?string
+    {
+        $rows = $this->connection->fetchAllAssociative(
+            "SELECT ST_AsGeoJSON(geometry) AS geometry, afai_mean AS afai
+             FROM sargassum_observation
+             WHERE detected_at >= NOW() - INTERVAL '30 days'
+               AND afai_mean > 0
+             ORDER BY detected_at DESC"
+        );
+
+        return $this->buildFeatureCollection($rows, [
+            'afai' => static fn($r) => (float) $r['afai'],
+        ]);
+    }
+
+    private function queryForecastsGeoJSON(int $horizon): ?string
+    {
+        $rows = $this->connection->fetchAllAssociative(
+            "SELECT ST_AsGeoJSON(geometry) AS geometry, confidence
+             FROM sargassum_forecast
+             WHERE time_horizon = :horizon
+               AND computed_at >= NOW() - INTERVAL '30 days'
+             ORDER BY computed_at DESC",
+            ['horizon' => $horizon]
+        );
+
+        return $this->buildFeatureCollection($rows, [
+            'confidence' => static fn($r) => (float) $r['confidence'],
+        ]);
+    }
+
+    /**
+     * @param array<array<string, mixed>> $rows
+     * @param array<string, callable(array<string, mixed>): mixed> $props
+     */
+    private function buildFeatureCollection(array $rows, array $props): ?string
+    {
+        if (empty($rows)) {
+            return null;
+        }
+
+        $features = [];
+        foreach ($rows as $row) {
+            $properties = [];
+            foreach ($props as $key => $fn) {
+                $properties[$key] = $fn($row);
+            }
+            $features[] = [
+                'type'       => 'Feature',
+                'geometry'   => json_decode($row['geometry'], true, 512, JSON_THROW_ON_ERROR),
+                'properties' => $properties,
+            ];
+        }
+
+        return json_encode(
+            ['type' => 'FeatureCollection', 'features' => $features],
+            JSON_THROW_ON_ERROR
+        );
+    }
+
+    private function runTippecanoe(string $geojson, string $outputDir, string $layer, SymfonyStyle $io): void
+    {
+        $tmpFile = sys_get_temp_dir() . '/tiles_' . uniqid() . '.geojson';
+        file_put_contents($tmpFile, $geojson);
+
+        try {
+            $cmd = sprintf(
+                'tippecanoe -e %s --force --layer=%s -Z%d -z%d --drop-densest-as-needed --quiet %s 2>&1',
+                escapeshellarg($outputDir),
+                escapeshellarg($layer),
+                self::MIN_ZOOM,
+                self::MAX_ZOOM,
+                escapeshellarg($tmpFile)
+            );
+
+            exec($cmd, $cmdOutput, $exitCode);
+
+            if ($exitCode !== 0) {
+                $errorMsg = implode("\n", $cmdOutput);
+                $this->logger->error('tippecanoe failed', ['output' => $errorMsg, 'dir' => $outputDir]);
+                $io->error("Tippecanoe a échoué : {$errorMsg}");
+            } else {
+                $io->success("→ {$outputDir}");
+            }
+        } finally {
+            @unlink($tmpFile);
+        }
+    }
+}

backend/src/Controller/StatusController.php

@@ -29,7 +29,27 @@ class StatusController extends AbstractController
              ORDER BY requested_at DESC LIMIT 1"
         );
 
+        // Healthcheck : données fraîches si dernière observation < 6h
+        $healthy = false;
+        $alertReason = null;
+
+        if ($obs !== false && $obs['detected_at'] !== null) {
+            $detectedAt = new \DateTimeImmutable($obs['detected_at'], new \DateTimeZone('UTC'));
+            $now        = new \DateTimeImmutable('now', new \DateTimeZone('UTC'));
+            $ageSeconds = $now->getTimestamp() - $detectedAt->getTimestamp();
+
+            if ($ageSeconds <= 6 * 3600) {
+                $healthy = true;
+            } else {
+                $alertReason = 'stale_data';
+            }
+        } else {
+            $alertReason = 'no_data';
+        }
+
         return $this->json([
+            'healthy'     => $healthy,
+            'alertReason' => $alertReason,
             'lastObservation' => $obs !== false ? [
                 'detectedAt'  => $obs['detected_at'],
                 'source'      => $obs['source'],
@@ -43,6 +63,6 @@ class StatusController extends AbstractController
                 'finishedAt'  => $job['processed_at'],
                 'retryCount'  => (int) $job['retry_count'],
             ] : null,
-        ]);
+        ], $healthy ? 200 : 503);
     }
 }