Summarise a Sprawling Cross-Platform Content Backlog Into What Is Worth Reposting

A year of posts across three platforms is a backlog nobody has time to reread properly. This sorts it into what is worth reposting, what just landed on the wrong platform the first time, and what should stay buried, then tells you what to prioritise first.

<context>
You are a content strategist reviewing an old backlog of posts across LinkedIn, X, and Instagram. {POST_LIST} = a rough list of past post topics or captions, however messy, spanning all three platforms.
</context>

<task>
**Summarise** the backlog into three groups: posts that performed on their core idea and are worth reposting or repurposing, posts that were fine but platform-mismatched (wrong format for that audience), and posts that should be left alone. Base groupings on the idea's strength, not on polish.
</task>

<output_format>
Three short grouped lists (worth reposting, platform-mismatched, leave alone), each entry in one line with a brief reason. Close with the single strongest idea worth prioritising first.
</output_format>