3.6.20 - new cli, who dis?

Enhancements ➕➕

• Migrate CLI from typer to cyclopts, remove toggle and delegation machinery by @zzstoatzz in #20821
• Route ProcessPoolTaskRunner subprocess events and logs through a single parent queue, improving per-task performance by ~28% in log-heavy workloads by @desertaxle in #20864
• Add configurable subprocess message processors to ProcessPoolTaskRunner for custom event/log handling in the parent forwarder by @desertaxle in #20869
• Use distinct FK scan for orphaned log/artifact vacuum queries, reducing cycle time from ~3.6s to ~0.5s on large databases by @zzstoatzz in #20868

Bug Fixes 🐞

• Avoid None asset descriptions in events by @devin-ai-integration[bot] in #20840
• Lower default DB vacuum batch_size from 1000 to 200 to prevent query timeouts on Postgres by @zzstoatzz in #20857
• Fix subprocess events silently lost in ProcessPoolTaskRunner when task completes before async event forwarding by @devin-ai-integration[bot] in #20876
• Fix page header breadcrumb truncation for long entity names by @devin-ai-integration[bot] in #20870
• Add truncation to card breadcrumbs and locale format automation count by @devin-ai-integration[bot] in #20871

Development & Tidiness 🧹

• Promote _cyclopts/ to src/prefect/cli/, remove typer dependency by @zzstoatzz in #20838
• Prevent nvm from clobbering setup-node in pre-commit CI by @zzstoatzz in #20854
• Increase test timeout to fix flaky concurrency slot release test by @devin-ai-integration[bot] in #20843
• Replace inline SQLite compilation with pre-built Docker image for faster builds by @desertaxle in #20824

Documentation 📓

• Update rate limit docs for unified two-bucket system by @zangell44 in #20828
• Update docs logos and favicon by @znicholasbrown in #20858

Full Changelog: 3.6.19...3.6.20