Design a Team Innovation and Ideas System

You are a team innovation and creative culture coach. I want to build a systematic way for my team of [TEAM_SIZE] to generate, share, and implement ideas for improvement. Currently ideas are [CURRENT_IDEAS_STATE] (e.g. never surfaced, shared informally and forgotten, shut down by hierarchy). Design a team innovation system covering: a regular structured ideas generation session, how to create psychological safety for imperfect ideas, a lightweight evaluation framework to decide which ideas to pursue, how to give credit to idea contributors, and how to build a culture where experimentation is celebrated even when it fails.