v0.9.0

Breaking Changes (MCP)

Last breaking-change window before semver lock. Tool count: 31 → 28.

• tandem_suggest deprecated — error stub pointing to tandem_comment. Hard-remove in v0.10.0.
• tandem_getContent removed — use tandem_getTextContent.
• tandem_getSelections removed — use tandem_checkInbox.
• tandem_setStatus merged into tandem_status — accepts optional write params.

Added

• /api/info endpoint (#441) — app version, MCP SDK version, tool count, platform
• Tabbed-left layout variant (#445) — side panel on the left
• App version in Settings footer (#435)
• View Changelog button in Settings (#437)
• Authorship data-tandem-author attributes (#443)
• Schema foundations (#440, #442, #444, #450) — 7 new settings fields, editor width min 40%, highlight palette 5→4 colors
• CI stdio smoke test (#341)

Fixed

• Cross-element edit merging (#456)
• Annotation decoration initial-sync race
• Channel checkpoint timing
• Auto-save spurious tab switches
• Event-bridge error handling
• MCP SDK version resolution

Changed

• Redesign gap audit resolved (#439) — 7 product decisions in ADR-026
• Distribution (#316, #317, #322) deferred to v0.13.0

See CHANGELOG.md for full details.