Part of #1946 — Redux → React Query migration (Stage 1). Part of the #1977 model-store dissolution (plan) — Layers D3 + D4. Two stacked PRs under one issue; depends on D1/D2 (#2088). Removes the last courseware bridge entries.

Goal: read the sections and coursewareMeta models from the courseware queries, convert the seven direct state.models selectors, and drop the coursewareMeta / sections / sequences / units mirrors from the bridge.

Context. coursewareMeta[courseId] is a merge: normalizeMetadata(...) from useCoursewareMetadata plus { id, title, sectionIds, hasScheduledContent } from useCoursewareOutline's courses map. sections comes only from the outline query. So each converted field reads from whichever of the two queries produces it.

Tasks — D3, sections (4) + coursewareMeta (17)

• sections: courseware/course/Course.jsx:36, sequence/Sequence.jsx:47, breadcrumbs/CourseBreadcrumbs.jsx:24, courseware/data/apiHooks.ts:52 (useSequenceIds).
• coursewareMeta → useCoursewareMetadata(courseId).data or useCoursewareOutline(courseId).data per field: alerts/sequence-alerts/hooks.js:22, course-home/progress-tab/certificate-status/CertificateStatus.jsx:23, courseware/course/ (12: Course.jsx:29, breadcrumbs/CourseBreadcrumbs.jsx:19, course-exit/CourseCelebration.jsx:52, course-exit/CourseExit.jsx:27, course-exit/utils.js:84, sequence/Sequence.jsx:41, sequence/Unit/UnitSuspense.jsx:22, sequence/Unit/hooks/useShouldDisplayHonorCode.js:13, sequence/lock-paywall/LockPaywall.jsx:27, sequence/sequence-navigation/hooks.js:14, sidebar/SidebarContextProvider.jsx:34, sidebar/sidebars/course-outline/hooks.js:26), courseware/social-share/SocialIcons.jsx:32, widgets/upgrade/src/UpgradePanel.jsx:28, courseware/data/apiHooks.ts:51.
• Move useSaveIntegritySignature's userNeedsIntegritySignature write (courseware/data/apiHooks.ts:225-231) onto the metadata query.
• Confirm the title collision is inert (see below).
• Update the useModel('coursewareMeta', …) example in courseware/course/sidebar/README.md:185.

Tasks — D4, the direct selectors

• CoursewareContainer.tsx:39,42,52 (coursewareMeta, sequences ×2) and redirects.ts:256,259,262,266 (sequences, sections ×2, coursewareMeta) → the owning queries; delete courseware/data/modelReader.ts.
• Remove the models: mirrors from useCoursewareMetadata, useCoursewareOutline and useSequenceMetadata in courseware/data/apiHooks.ts.

Verify: courseware loads, breadcrumbs render, all five redirect rules still fire (resume, section→sequence, section/unit→unit, unit→sequence/unit, outline failure), the integrity-signature modal dismisses and stays dismissed; git grep "readModels\|state.models" src returns only the model store itself and setupTest.js; no react-redux import left in src/courseware/.

Findings that shape the task list

• coursewareMeta.title is written by both queries — data.name from normalizeMetadata, and the outline's own title — so today the last write wins. No reader of coursewareMeta.title was found, so the collision looks inert; confirm before picking a source.
• useSequenceIds is itself a model reader (apiHooks.ts:51-52: coursewareMeta.sectionIds then useModels('sections', …)), so it converts here even though it lives in the data layer, and CoursewareContainer/UnitNavigationEffortEstimate/sequence-navigation/hooks.js inherit the fix.
• redirects.ts reads sections[sequenceId] (sectionViaSequenceId) — i.e. it deliberately looks a section up by the route's sequence id to detect a section-shaped URL. Preserve that, it is not a typo.
• This is where react-redux leaves the courseware subtree, so it is the natural place to check that nothing but the model store itself still imports it.