corresync v0.8.6

Local-first, provider-neutral email and calendar MCP server and CLI for
accounts the signed-in human already controls. Verify the checksum,
Sigstore identity, and compatibility evidence before connecting a sensitive
account.

Changelog

• a9e4d0b ci(release): separate v0.8 maintenance line (#150)
• 70b65f8 docs(architecture): focus product on CLI and MCP (#143)
• 3430fbe docs(release): prepare v0.8.6 (#154)
• 4e20b7b feat(setup): select account services (#152)