Plan vs actual

Running plan and actuals on one ledger means both post to the same double-entry core, separated by the scenario tag — no copies, no drift. Planning modules read and write that ledger directly at PH-1; delta-scenario storage, where a plan inherits the actual base instead of holding its own rows, is on the roadmap.

Canonical definition from the Ledgerbook glossary. Definitions are the product vocabulary — the same terms the API and MCP tools use.