WSL 도커 전환과 trixie-slim 로컬 실행 복구 반영

baron-sso/backend/Dockerfile

@@ -1,9 +1,11 @@
-FROM golang:1.26.2-alpine
+FROM golang:1.26.2-trixie
 
 WORKDIR /app
 
 # Install git for go mod download if needed
-RUN apk add --no-cache git
+RUN apt-get update \
+	&& apt-get install -y --no-install-recommends git ca-certificates \
+	&& rm -rf /var/lib/apt/lists/*
 
 # Pre-copy go.mod/sum to cache dependencies
 COPY go.mod go.sum ./