refactor(service_spec_gen): split into 6 packages (types, client, config, normalize, spec, main) + .gitignore

- Split 741-line monolith into 6 independent packages
- All functions exported, no circular deps
- Build: go build -o bin/service_spec_gen ./tools/service_spec_gen/
- Script 01_generate_yamls.sh: go run → ./bin/service_spec_gen
- Add bin/ to .gitignore

devops/01_generate_yamls.sh

@@ -229,7 +229,7 @@ PY
       NUBES_SERVICE_NAME="$svc_name" \
       NUBES_API_ENDPOINT="$API_ENDPOINT" \
       NUBES_OUTPUT_DIR="$YAML_OUTPUT_DIR" \
-      go run ./tools/service_spec_gen
+      ./bin/service_spec_gen
     ) && success=1 || success=0
 
     if [[ "$success" -eq 1 ]]; then