fix: use service hostname instead of localhost for PostgreSQL

- Remove port mapping (5432:5432) to avoid port conflicts on runner
- Use 'postgres' hostname instead of 'localhost' to access service
- Service containers in Actions are accessible via their service name
- Fixes 'port is already allocated' error on self-hosted runners

.forgejo/workflows/build.yaml

@@ -28,8 +28,6 @@ jobs:
           --health-interval 10s
           --health-timeout 5s
           --health-retries 5
-        ports:
-          - 5432:5432
 
     steps:
       - name: Checkout code
@@ -78,7 +76,7 @@ jobs:
 
       - name: Wait for PostgreSQL
         run: |
-          until pg_isready -h localhost -p 5432 -U postgres; do
+          until pg_isready -h postgres -p 5432 -U postgres; do
             echo "Waiting for PostgreSQL..."
             sleep 2
           done
@@ -88,7 +86,7 @@ jobs:
         run: mix ecto.create
         env:
           MIX_ENV: test
-          DATABASE_URL: postgresql://postgres:postgres@localhost:5432/towerops_test
+          DATABASE_URL: postgresql://postgres:postgres@postgres:5432/towerops_test
 
       - name: Check code formatting
         run: mix format --check-formatted
@@ -105,7 +103,7 @@ jobs:
         run: mix test --warnings-as-errors
         env:
           MIX_ENV: test
-          DATABASE_URL: postgresql://postgres:postgres@localhost:5432/towerops_test
+          DATABASE_URL: postgresql://postgres:postgres@postgres:5432/towerops_test
 
   build:
     runs-on: ubuntu-22.04