Prototype 0.1.0

Changelog

• Added main menu with system boot text, current filing summary, display toggles, and spreadsheet system previews.
• Added selectable spreadsheet systems: LedgerOS, Millennium Office, Digits, CloudLedger, ForecastOS, and DaemonGrid.
• Added workbook books with distinct board conditions and objectives.
• Added placement preview for formula output, instability, pressure, affected cells, and terrain effects.
• Added formula identities and layout desires.
• Added instability, pressure, workbook state, corruption, cleanup, and error systems.
• Added recalculation feedback: firing cells, dependency trail, combo shelf, recalculation event alerts, and Audit breakdown.
• Added settings for reduce motion, subdued effects, compact mode, large text, animation speed, and autosave.
• Added local save, reset, import, and export.

Known prototype gaps:

• Tutorial levels are still pending.
• Run contracts and difficulty heat are planned but not implemented.
• Balance is early and expected to change.
• Audio is not implemented.
• Desktop browser play is the target for this first public build.