feat(ci): add rollback mechanism and Telegram notifications

CI/CD Pipeline Improvement - Add automated rollback on deployment
failure and Telegram notifications for CI/deploy status.

Changes:
- scripts/deploy-prod.sh: Add rollback_save_image(), rollback_restore_image(),
  and telegram_notify() functions
- scripts/deploy-prod.sh: Save current Docker image before building new one
- scripts/deploy-prod.sh: Rollback to previous image on health check failure
- .gitea/workflows/ci.yaml: Add Telegram notifications for CI failures
- memento-note/eslint.config.mjs: Disable experimental React Compiler rules

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/deploy-prod.sh

@@ -2,10 +2,71 @@
 # Déploiement prod sur 192.168.1.190 — exécuter SUR LE SERVEUR (runner docker-host).
 set -euo pipefail
 
+# Telegram notification function
+telegram_notify() {
+  local status="$1"
+  local message="$2"
+  local bot_token="${TELEGRAM_BOT_TOKEN:-}"
+  local chat_id="${TELEGRAM_CHAT_ID:-}"
+
+  if [ -z "$bot_token" ] || [ -z "$chat_id" ]; then
+    echo "TELEGRAM_BOT_TOKEN or TELEGRAM_CHAT_ID not set — skipping notification"
+    return 0
+  fi
+
+  local emoji="✅"
+  if [ "$status" = "failure" ]; then
+    emoji="❌"
+  elif [ "$status" = "rollback" ]; then
+    emoji="🔄"
+  fi
+
+  local commit_msg=$(git log -1 --pretty=format:"%s" 2>/dev/null || echo "unknown")
+  # Escape markdown special characters in commit message
+  commit_msg=$(echo "$commit_msg" | sed 's/[_*`[\]()~>#+=|{}.!\\-]/\\&/g')
+  local commit_short="${GIT_COMMIT:0:8}"
+
+  curl -s -X POST "https://api.telegram.org/bot${bot_token}/sendMessage" \
+    -d "chat_id=${chat_id}" \
+    -d "text=${emoji} Momento Deploy ${status}
+Commit: ${commit_short}
+Message: ${commit_msg}
+Details: ${message}" \
+    -d "parse_mode=Markdown" > /dev/null 2>&1 || echo "Telegram notification failed"
+}
+
+# Rollback functions
+rollback_save_image() {
+  echo "=== Saving current image for rollback ==="
+  if docker images --format '{{.Repository}}:{{.Tag}}' | grep -q "^memento-memento-note:latest"; then
+    docker tag memento-memento-note:latest memento-memento-note:rollback || echo "WARN: Failed to tag rollback image"
+    echo "Rollback image saved: memento-memento-note:rollback"
+  else
+    echo "WARN: No current memento-note image found to save"
+  fi
+}
+
+rollback_restore_image() {
+  echo "=== Rolling back to previous image ==="
+  if docker images --format '{{.Repository}}:{{.Tag}}' | grep -q "^memento-memento-note:rollback"; then
+    docker tag memento-memento-note:rollback memento-memento-note:latest || echo "ERROR: Failed to restore rollback image"
+    docker compose up -d --force-recreate memento-note || echo "ERROR: Failed to restart container"
+    echo "Rollback completed"
+  else
+    echo "ERROR: No rollback image found"
+    return 1
+  fi
+}
+
 ROOT="${DEPLOY_ROOT:-/opt/memento}"
 ARTIFACT_TGZ="${ARTIFACT_TGZ:-}"
 EXPECTED_COMMIT="${EXPECTED_COMMIT:-}"
 
+# Health check configuration: 24 iterations × 5 seconds = 2 minutes total timeout
+# This allows Next.js cold start time while keeping feedback fast
+HEALTH_CHECK_MAX_ITERATIONS=24
+HEALTH_CHECK_SLEEP_SECONDS=5
+
 cd "$ROOT"
 git config --global --add safe.directory "$ROOT" 2>/dev/null || true
 git fetch origin main
@@ -44,6 +105,9 @@ fi
 export COMPOSE_DOCKER_CLI_BUILD=1 DOCKER_BUILDKIT=1
 export GIT_COMMIT
 
+# Save current image for rollback before building new one
+rollback_save_image
+
 if [ -n "$ARTIFACT_TGZ" ] && [ -f "$ARTIFACT_TGZ" ]; then
   echo "=== Fast image (CI artifact) ==="
   tar xzf "$ARTIFACT_TGZ" -C memento-note/
@@ -83,7 +147,7 @@ fi
 
 nginx -t 2>/dev/null && systemctl reload nginx 2>/dev/null || true
 
-for i in $(seq 1 24); do
+for i in $(seq 1 "$HEALTH_CHECK_MAX_ITERATIONS"); do
   BODY=$(docker compose exec -T memento-note node -e "require('http').get('http://localhost:3000/api/build-info',r=>{let d='';r.on('data',c=>d+=c);r.on('end',()=>{console.log(d);process.exit(0)})}).on('error',()=>process.exit(1))" 2>/dev/null || true)
   ACTUAL=$(echo "$BODY" | jq -r '.commit // empty' 2>/dev/null || true)
   if [ "$ACTUAL" = "$GIT_COMMIT" ]; then
@@ -108,11 +172,17 @@ for i in $(seq 1 24); do
       fi
     fi
     docker compose ps
+    telegram_notify "success" "Deployment successful — app is healthy"
     exit 0
   fi
-  sleep 5
+  sleep "$HEALTH_CHECK_SLEEP_SECONDS"
 done
 
 echo "ERROR: build-info=$ACTUAL expected=$GIT_COMMIT"
 docker logs memento-web --tail=40
+
+# Rollback on health check failure
+rollback_restore_image
+telegram_notify "rollback" "Health check failed — rolled back to previous version"
+
 exit 1