feat: Introduce service app token retrieval and enhance OAuth flow

get_service_app_token.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+"""
+Get a fresh service app token for external use
+
+Usage:
+    python3 get_service_app_token.py              # Print token to stdout
+    python3 get_service_app_token.py | pbcopy     # Copy to clipboard (macOS)
+    TOKEN=$(python3 get_service_app_token.py)     # Save to variable
+"""
+
+from token_manager import TokenManager
+import sys
+
+def main():
+    try:
+        tm = TokenManager()
+        token = tm.get_service_app_token()
+
+        # Print only the token to stdout (clean output for piping)
+        print(token)
+
+    except Exception as e:
+        print(f"Error: {e}", file=sys.stderr)
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()
+