fix: Align all Go versions and ensure consistent module configuration

- Update Dockerfile from golang:1.21 to golang:1.25.3 to match go.mod
- Update Dockerfile.dev from golang:1.25 to golang:1.25.3 for consistency
- Add GO111MODULE=on to all Go-related CI steps for explicit module mode
- Ensures all environments (CI, Docker, local) use Go 1.25.3 consistently

.gitea/workflows/ci.yml

@@ -72,6 +72,8 @@ jobs:
           go-version: '1.25.3'
       - name: Download dependencies
         working-directory: bugulma/backend
+        env:
+          GO111MODULE: on
         run: go mod download
       - name: Vet
         working-directory: bugulma/backend
@@ -85,9 +87,13 @@ jobs:
           go vet ./...
       - name: Test
         working-directory: bugulma/backend
+        env:
+          GO111MODULE: on
         run: go test -v -race -coverprofile=coverage.out ./...
       - name: Coverage
         working-directory: bugulma/backend
+        env:
+          GO111MODULE: on
         run: go tool cover -html=coverage.out -o coverage.html
 
   backend-build:

bugulma/backend/Dockerfile

@@ -1,5 +1,5 @@
 # Production Dockerfile for Turash backend
-FROM golang:1.21-alpine AS builder
+FROM golang:1.25.3-alpine AS builder
 
 # Set working directory
 WORKDIR /app

bugulma/backend/Dockerfile.dev

@@ -1,5 +1,5 @@
 # Development Dockerfile for hot reload
-FROM golang:1.25-alpine AS builder
+FROM golang:1.25.3-alpine AS builder
 
 # Install air for hot reload
 RUN go install github.com/air-verse/air@latest