v0.7.3

Changelog

• 4ee6c49: cli: add doctor, service install, and a setup that actually registers MCP (@DDDD177)
• 9366e1b: dashboard: History/replay panel — what agents did (hash-chained audit) (@DDDD177)
• d6fdad9: dashboard: read-only Policies panel (+ /api/policies) (@DDDD177)
• 2dace14: fix(ssh): remove tmux wrapping — it broke remote sessions on hosts with tmux (@DDDD177)