update.sh: switch backend sync to git pull instead of rsync

Servers now have git repos initialized tracking origin/main.
Step 3 does git pull --ff-only instead of rsync. Frontend dist
is still rsynced since it's gitignored.

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

update.sh

@@ -18,7 +18,7 @@
 # Schritte (Reihenfolge ist kritisch):
 #   1. Tests auf Server 137 ausführen (via SSH)
 #   2. Frontend bauen (lokal, npm run build)
-#   3. Backend-Code auf Server(n) synchronisieren (rsync)
+#   3. git pull origin main auf Server(n)
 #   4. Alembic-Migration auf Server ausführen
 #   5. Service neustarten
 #   6. Health-Check (3 Versuche)
@@ -347,37 +347,30 @@ for server in "${SERVERS[@]}"; do
     SERVER_OK=true
 
     # -------------------------------------------------------------------------
-    # SCHRITT 3: Backend synchronisieren
+    # SCHRITT 3: git pull vom Gitea
     # -------------------------------------------------------------------------
-    step "[$SERVER_SHORT] Schritt 3: Backend-Code synchronisieren"
-    info "rsync: $BACKEND_DIR/ → $server:$REMOTE_PATH/backend/"
+    step "[$SERVER_SHORT] Schritt 3: git pull (origin/main)"
 
-    RSYNC_EXCLUDE=(
-        "--exclude=__pycache__"
-        "--exclude=*.pyc"
-        "--exclude=.env"
-        "--exclude=venv/"
-        "--exclude=.git/"
-        "--exclude=*.egg-info/"
-        "--exclude=.pytest_cache/"
-        "--exclude=htmlcov/"
-        "--exclude=.coverage"
-    )
+    GIT_PULL_CMD="git config --global --add safe.directory $REMOTE_PATH 2>/dev/null; cd $REMOTE_PATH && git pull --ff-only origin main 2>&1"
 
-    if run_rsync -avz "${RSYNC_EXCLUDE[@]}" \
-        "$BACKEND_DIR/" \
-        "$server:$REMOTE_PATH/backend/" ; then
-        ok "Backend synchronisiert"
-        step_record "3. Backend-Sync [$SERVER_SHORT]" "OK"
+    if $OPT_DRYRUN; then
+        echo -e "    ${YELLOW}[DRY-RUN]${RESET} ssh $server \"$GIT_PULL_CMD\""
+        step_record "3. git pull [$SERVER_SHORT]" "SKIP"
     else
-        RSYNC_RC=$?
-        fail "rsync FEHLGESCHLAGEN (Exit-Code: $RSYNC_RC)"
-        fail "Befehl war: rsync -avz ${RSYNC_EXCLUDE[*]} $BACKEND_DIR/ $server:$REMOTE_PATH/backend/"
-        step_record "3. Backend-Sync [$SERVER_SHORT]" "FAIL"
-        SERVER_OK=false
-        ALL_SERVERS_OK=false
-        warn "Server $server wird übersprungen (rsync fehlgeschlagen)"
-        continue
+        GIT_OUTPUT=$(ssh -o ConnectTimeout=30 -o BatchMode=yes "$server" "$GIT_PULL_CMD" 2>&1)
+        GIT_RC=$?
+        echo "$GIT_OUTPUT" | while IFS= read -r line; do info "$line"; done
+        if [ $GIT_RC -eq 0 ]; then
+            ok "git pull erfolgreich"
+            step_record "3. git pull [$SERVER_SHORT]" "OK"
+        else
+            fail "git pull FEHLGESCHLAGEN (Exit-Code: $GIT_RC)"
+            step_record "3. git pull [$SERVER_SHORT]" "FAIL"
+            SERVER_OK=false
+            ALL_SERVERS_OK=false
+            warn "Server $server wird übersprungen (git pull fehlgeschlagen)"
+            continue
+        fi
     fi
 
     # -------------------------------------------------------------------------