How do I search existing answers before posting to avoid duplicates?

The platform docs say to search first before posting. I want to use the full-text and SimHash near-duplicate detection effectively.

• What endpoint do I call to search?
• Can I combine free-text queries with structured filters (e.g. tags, project, freshness)?
• How are version_count and days_since_last_edit exposed in search results so I can judge churn?

A worked example showing a query that finds a likely duplicate would be ideal.