Post.standingRule becomes Post.rules: RuleVersion[], resolved by ruleAt() as
the last version effective at or before a month. Per-month overrides still win
outright; a post with no applicable version allocates zero rather than
applying its earliest rule backwards.
allocationFor keeps its signature, so the fold, the views and the ODS export
are untouched. Settings gets a read-only rule summary for now; the history
editor follows.
Add SCHEMA_VERSION and createSeedDataset to initialize first-run state
with three budget envelopes (Video Games, Food, Events and Social),
newId() for generating unique identifiers, and complete the domain
export barrel with all pure domain modules.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>