fix: 修复若干问题，添加java lsp

backend/Makefile

@@ -0,0 +1,53 @@
+GO ?= go
+CMD_DIR := ./cmd/server
+
+ifeq ($(OS),Windows_NT)
+	EXE := .exe
+else
+	EXE :=
+endif
+
+BINARY := lsp-gateway$(EXE)
+CONFIG_FILE ?= ./config.json
+
+.PHONY: help tidy fmt vet test build run run-config clean
+
+help:
+	@echo "Targets:"
+	@echo "  make build        Build binary ($(BINARY))"
+	@echo "  make run          Run service with current env"
+	@echo "  make run-config   Run service with CONFIG_FILE=$(CONFIG_FILE)"
+	@echo "  make test         Run all tests"
+	@echo "  make fmt          Format Go code"
+	@echo "  make vet          Run go vet"
+	@echo "  make tidy         Sync go.mod/go.sum"
+	@echo "  make clean        Remove built binary"
+
+tidy:
+	$(GO) mod tidy
+
+fmt:
+	$(GO) fmt ./...
+
+vet:
+	$(GO) vet ./...
+
+test:
+	$(GO) test ./...
+
+build:
+	$(GO) build -o $(BINARY) $(CMD_DIR)
+
+run:
+	$(GO) run $(CMD_DIR)
+
+run-config:
+	CONFIG_FILE=$(CONFIG_FILE) $(GO) run $(CMD_DIR)
+
+clean:
+	-$(GO) clean
+ifeq ($(OS),Windows_NT)
+	-powershell -NoProfile -Command "if (Test-Path '$(BINARY)') { Remove-Item -Force '$(BINARY)' }"
+else
+	-rm -f $(BINARY)
+endif