Drops dead `id` props and `scroll-mt-28` classes from admin section
components (load-bearing in v1.4 monolithic admin, dead since the v1.5
phase-4b dynamic-route split). Also removes the unused
`LEGACY_ANCHOR_TO_SLUG` map, the `admin-shell` re-export shim, the
`BERLIN_TZ` and duplicate `MS_PER_DAY` constants, the verbose
`AdminSectionPage` docstring, the `useEffect` paraphrase comment in
`ai-section`, and rewrites the `_exhaustive: never` exhaustiveness
guard to the modern `slug satisfies never` form. `UserManagementSection`
now reads `currentUserId` via `useAuth()` instead of accepting it as a
prop.
Findings 1, 2, 3, 4, 6, 7, 8, 11, 15, 16, 17 from
.planning/phase-6-simplify-findings.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Mirrors the v1.4 settings split for the v1.5 admin refactor. Adds the
shell, the slug constants, the dynamic-route page, and the client-only
renderer that picks the right section component for each slug. The
existing admin sections continue to live in src/components/admin/*.tsx;
this scaffolding wires them into per-route bundles.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
