v0.21.0

What's Changed

• Update flake.nix for v0.20.0 by @wesm in #161
• Add analyze and fix commands to README by @wesm in #163
• Include current UTC date in review prompts by @wesm in #164
• Check for existing review jobs in enqueueIfNeeded to prevent duplicates by @wesm in #166
• Fix shell wildcard expansion in analyze from subdirectories by @wesm in #165
• Add --unaddressed flag to fix command for batch fixing by @wesm in #169
• Allow configuring changelog agent via CHANGELOG_AGENT env var by @wesm in #168
• Update flake.nix for v0.20.1 by @wesm in #167
• Refactor test suite: reduce boilerplate, improve isolation and safety by @wesm in #170
• Add Cursor agent, check-agents command, and show --prompt by @wesm in #172
• Shared fix logic, workflow config, daemon resilience, and UX improvements by @wesm in #173

Full Changelog: v0.20.0...v0.21.0