fix[build]: make environment variables optional for editable installs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: aschlean

setup.py

@@ -11,27 +11,30 @@
 PACKAGE_OUT_REL = "golf/_endpoints.py"
 
 
-def render_endpoints():
+def render_endpoints(require_env_vars: bool = True):
     """Render the endpoints template with environment variables."""
     tpl_path = pathlib.Path(TEMPLATE_REL)
     if not tpl_path.exists():
         raise FileNotFoundError(f"Template not found: {tpl_path}")
 
-    # Require environment variables - no defaults with real URLs
+    # Get environment variables
     platform_url = os.environ.get("GOLF_PLATFORM_API_URL")
     otel_url = os.environ.get("GOLF_OTEL_ENDPOINT") 
 
-    if not platform_url or not otel_url:
+    # For production builds, require environment variables
+    # For development/editable installs, use fallback values
+    if require_env_vars and (not platform_url or not otel_url):
         raise SystemExit(
             "Missing required environment variables for URL injection:\n"
             "  GOLF_PLATFORM_API_URL\n" 
             "  GOLF_OTEL_ENDPOINT\n"
             "Set these before building the package."
         )
 
+    # Use environment variables if available, otherwise fallback to development URLs
     values = {
-        "PLATFORM_API_URL": platform_url,
-        "OTEL_ENDPOINT": otel_url,
+        "PLATFORM_API_URL": platform_url or "http://localhost:8000/api/resources",
+        "OTEL_ENDPOINT": otel_url or "http://localhost:4318/v1/traces",
     }
 
     try:
@@ -49,8 +52,8 @@ def run(self):
         # First run the normal build
         super().run()
 
-        # Then render endpoints into the build_lib
-        rendered = render_endpoints()
+        # Then render endpoints into the build_lib (require env vars for production builds)
+        rendered = render_endpoints(require_env_vars=True)
         out_file = pathlib.Path(self.build_lib) / PACKAGE_OUT_REL
         out_file.parent.mkdir(parents=True, exist_ok=True)
         out_file.write_text(rendered, encoding="utf-8")
@@ -64,8 +67,8 @@ def run(self):
         # Run normal develop command first
         super().run()
 
-        # Generate a working copy file for editable installs
-        rendered = render_endpoints()
+        # Generate a working copy file for editable installs (use fallback URLs if env vars missing)
+        rendered = render_endpoints(require_env_vars=False)
         # For editable installs, write into the source tree so imports work
         src_file = pathlib.Path("src") / PACKAGE_OUT_REL
         src_file.parent.mkdir(parents=True, exist_ok=True)