Fix: harden local dev startup flow

Docker/docker-compose.local.dev.yaml

@@ -1,12 +1,16 @@
 x-backend-service: &backend-service
   image: moku/work-backend:dev
   restart: unless-stopped
+  user: "${LOCAL_UID:-1000}:${LOCAL_GID:-1000}"
   env_file:
     - ../Env/.env.local
   environment:
     DATABASE_URL: postgres://moku:moku_dev_password@postgres:5432/moku?sslmode=disable
     VALKEY_URL: redis://valkey:6379/0
     POSIX_ROOT: /posix
+    HOME: /tmp/home
+    GOMODCACHE: /tmp/go/pkg/mod
+    GOCACHE: /tmp/go-build
   depends_on:
     postgres:
       condition: service_healthy
@@ -15,8 +19,8 @@ x-backend-service: &backend-service
   volumes:
     - ../Backend:/app
     - ../POSIX:/posix
-    - moku_work_backend_go_pkg:/go/pkg/mod
-    - moku_work_backend_go_build:/root/.cache/go-build
+    - moku_work_backend_go_pkg:/tmp/go/pkg/mod
+    - moku_work_backend_go_build:/tmp/go-build
 
 services:
   postgres: