Add an append-only ledger of entitlement set rule changes with per-pool
effect rows, a preview-and-commit rule change flow, and an automatic
drain that settles deferred recomputations. Rules gain a tier reduction
policy, resource keys declare over-limit behavior, and the materializer
now lowers limits when a rule stops applying.
Add entitlement set rule change ledger and preview flow
Add an append-only ledger of entitlement set rule changes with a
preview-and-commit operator flow. Rule writes now go through an enclosed
`core.commit_rule_change` function that files an act row and one
obligation per carrying pool, with a drain workflow settling deferred
recomputations. The preview dry-runs the materializer with a rule
overlay and renders per-pool buckets, reduction-policy disclosures, and
provider over-limit consequences. Materializing transactions take a
shared advisory rendezvous that rule changes hold exclusively, enforced
by a possession assertion. Add History and Entitlement changes surfaces,
a rule-less warning on five product-selection surfaces, and a
`tier_reduction_policy` column that gates FedWiki parking.
Squash the pre-production migration history into fresh core, fedwiki,
and stripe baselines and reduce the canonical source list to those
three streams.
Update sqlc configs, generated queries, raw SQL, tests, and docs while
keeping provider tables schema-qualified.
BREAKING: existing local database volumes must be wiped because goose
version history restarts from the new baselines.