Where’s the prettiest place you’ve never eaten?  That would be Hideaway at the Oceana Beach Club Hotel, the secretive, sexy hotel nestled into a quiet residential neighborhood at 849 Ocean Avenue in Santa Monica.  Why is it the prettiest and why have you never eaten there?  Originally opened with a “guest only” policy (later abandoned), this little charmer boasted an adventurous (if small) “coastal California cuisine” menu, a seaside clubhouse  feel, and jaw-dropping views of Palisades Park and the ocean beyond through enormous picture windows.  Well, all that is about to change.  Hideaway at the  Oceana is now closed for a major renovation.  Gone will be the clubhouse feel, to be replaced with a sleek Deco design and a fireplace.  The menu will be completely revamped as well.  Sumptuous sunset views will stay.  Look for a December opening…