Refactor DeerFlow to use Gateway's LangGraph-compatible API

- Updated documentation and comments to reflect the transition from LangGraph Server to Gateway.
- Changed default URLs in ChannelManager and tests to point to Gateway.
- Removed references to LangGraph Server in deployment scripts and configurations.
- Updated Nginx configuration to route API traffic to Gateway.
- Adjusted frontend configurations to utilize Gateway's API.
- Removed LangGraph service from Docker Compose files, consolidating services under Gateway.
- Added regression tests to ensure Gateway integration works as expected.

Co-authored-by: Copilot <copilot@github.com>

scripts/deploy.sh

@@ -3,52 +3,38 @@
 # deploy.sh - Build, start, or stop DeerFlow production services
 #
 # Commands:
-#   deploy.sh [--MODE]           — build + start (default: --standard)
+#   deploy.sh                    — build + start
 #   deploy.sh build              — build all images (mode-agnostic)
-#   deploy.sh start [--MODE]     — start from pre-built images (default: --standard)
+#   deploy.sh start              — start from pre-built images
 #   deploy.sh down               — stop and remove containers
 #
-# Runtime modes:
-#   --standard  (default)  All services including LangGraph server.
-#   --gateway              No LangGraph container; nginx routes /api/langgraph/*
-#                          to the Gateway compat API instead.
-#
 # Sandbox mode (local / aio / provisioner) is auto-detected from config.yaml.
 #
 # Examples:
-#   deploy.sh                    # build + start in standard mode
-#   deploy.sh --gateway          # build + start in gateway mode
+#   deploy.sh                    # build + start
 #   deploy.sh build              # build all images
-#   deploy.sh start --gateway    # start pre-built images in gateway mode
+#   deploy.sh start              # start pre-built images
 #   deploy.sh down               # stop and remove containers
 #
 # Must be run from the repo root directory.
 
 set -e
 
-RUNTIME_MODE="standard"
-
 case "${1:-}" in
     build|start|down)
         CMD="$1"
         if [ -n "${2:-}" ]; then
-            case "$2" in
-                --standard) RUNTIME_MODE="standard" ;;
-                --gateway)  RUNTIME_MODE="gateway" ;;
-                *) echo "Unknown mode: $2"; echo "Usage: deploy.sh [build|start|down] [--standard|--gateway]"; exit 1 ;;
-            esac
+            echo "Unknown argument: $2"
+            echo "Usage: deploy.sh [build|start|down]"
+            exit 1
         fi
         ;;
-    --standard|--gateway)
-        CMD=""
-        RUNTIME_MODE="${1#--}"
-        ;;
     "")
         CMD=""
         ;;
     *)
         echo "Unknown argument: $1"
-        echo "Usage: deploy.sh [build|start|down] [--standard|--gateway]"
+        echo "Usage: deploy.sh [build|start|down]"
         exit 1
         ;;
 esac
@@ -212,7 +198,7 @@ if [ "$CMD" = "build" ]; then
     echo "  ✓ Images built successfully"
     echo "=========================================="
     echo ""
-    echo "  Next: deploy.sh start [--gateway]"
+    echo "  Next: deploy.sh start"
     echo ""
     exit 0
 fi
@@ -225,23 +211,14 @@ echo "=========================================="
 echo ""
 
 # ── Detect runtime configuration ────────────────────────────────────────────
-# Only needed for start / up — determines which containers to launch.
+# Only needed for start / up — determines whether provisioner is launched.
 
 sandbox_mode="$(detect_sandbox_mode)"
 echo -e "${BLUE}Sandbox mode: $sandbox_mode${NC}"
 
-echo -e "${BLUE}Runtime mode: $RUNTIME_MODE${NC}"
+echo -e "${BLUE}Runtime: Gateway embedded agent runtime${NC}"
 
-case "$RUNTIME_MODE" in
-    gateway)
-        export LANGGRAPH_UPSTREAM=gateway:8001
-        export LANGGRAPH_REWRITE=/api/
-        services="frontend gateway nginx"
-        ;;
-    standard)
-        services="frontend gateway langgraph nginx"
-        ;;
-esac
+services="frontend gateway nginx"
 
 if [ "$sandbox_mode" = "provisioner" ]; then
     services="$services provisioner"
@@ -282,17 +259,13 @@ fi
 
 echo ""
 echo "=========================================="
-echo "  DeerFlow is running! ($RUNTIME_MODE mode)"
+echo "  DeerFlow is running!"
 echo "=========================================="
 echo ""
 echo "  🌐 Application: http://localhost:${PORT:-2026}"
 echo "  📡 API Gateway: http://localhost:${PORT:-2026}/api/*"
-if [ "$RUNTIME_MODE" = "gateway" ]; then
-    echo "  🤖 Runtime:     Gateway embedded"
-    echo "  API:            /api/langgraph/* → Gateway (compat)"
-else
-    echo "  🤖 LangGraph:   http://localhost:${PORT:-2026}/api/langgraph/*"
-fi
+echo "  🤖 Runtime:     Gateway embedded"
+echo "  API:            /api/langgraph/* → Gateway"
 echo ""
 echo "  Manage:"
 echo "    make down        — stop and remove containers"