In Rachel Lambert’s dreamlike indie “Sometimes I Think About Dying,” our heroine’s life is on mute: visually, sonically and emotionally. An office worker in a coastal Oregon town, Fran (Daisy Ridley) is the silent center of this story. She quietly moves through her workday in the drab offices of a local port authority, goes home, microwaves a meal and eats it standing alone in her dim kitchen. Her favorite food is cottage cheese. But inside her mind, surreal and vivid images intrude on her thoughts — her body hanging like a rag doll from the hook of a crane, lying on a forest floor covered in …