Fix CI build and update Makefile to build all services

- Add $HOME/go/bin to PATH using $GITHUB_PATH for protoc plugins
- Update Makefile build target to build all service binaries:
  - platform, api-gateway, auth-service, identity-service, authz-service, audit-service
- Update CI workflow to use 'make build' instead of individual commands
- Upload all service binaries as CI artifacts
- Fixes protoc plugin discovery and ensures all services are built

.github/workflows/ci.yml

@@ -38,6 +38,7 @@ jobs:
           apk add --no-cache protobuf-dev protoc
           go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
           go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
+          echo "$HOME/go/bin" >> $GITHUB_PATH
 
       - name: Generate protobuf files
         run: make generate-proto
@@ -102,6 +103,7 @@ jobs:
           apk add --no-cache protobuf-dev protoc
           go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
           go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
+          echo "$HOME/go/bin" >> $GITHUB_PATH
 
       - name: Generate protobuf files
         run: make generate-proto
@@ -147,6 +149,7 @@ jobs:
           apk add --no-cache protobuf-dev protoc
           go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
           go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
+          echo "$HOME/go/bin" >> $GITHUB_PATH
 
       - name: Generate protobuf files
         run: make generate-proto
@@ -159,9 +162,7 @@ jobs:
           fi
 
       - name: Build
-        run: |
-          go build -v -o bin/platform ./cmd/platform
-          go build -v -o bin/api-gateway ./cmd/api-gateway
+        run: make build
 
       - name: Upload build artifacts
         uses: actions/upload-artifact@v3
@@ -170,6 +171,10 @@ jobs:
           path: |
             bin/platform
             bin/api-gateway
+            bin/auth-service
+            bin/identity-service
+            bin/authz-service
+            bin/audit-service
           retention-days: 7
 
   fmt: