Batch H0 of the hardening plan: freeze the JSON key SETS of every
load-bearing surface so H1-H7 can only change them additively.
- cmd/server/tests/contract_pins_test.go: 14 tests / ~30 subtests pinning
progress GET+PUT, the KOReader plugin surfaces (progress push/pull,
library, bookmarks), the Kobo adapter shapes (initialization, markup,
sync-from-server), collections detail all four branches + preview,
series JSON, search rows, dashboard sections, media list BOTH branches
(raw sqlc rows vs resolved 38-key map), and SSR smoke for
bookshelf/collections/series/tags.
- docs/contract_pins.md: the pinned-shape inventory + the rule that a
batch widening a shape must widen the pin and this doc in one commit.
Suite is green on the unmodified tree at b4ae423. KOReader/Kobo/progress
pins are the hard freeze (the plugin is an external client).