App #853 targets staging and closes #852 on merge. Loading, missing and quoted prices share a fixed-height single line, using native font fitting for long loading text. The type-mode grouping/filter header remains pinned during product scrolling with an opaque themed background. The series accordion tree remains non-sticky.

The outlined All series action sits at the upper right beside the grouping tabs, with a left arrow and compact fitting labels. It clears only the selected series while preserving series grouping. Existing catalogue IDs, paging, browse-state restoration and holdings are unchanged.

Validation: 3,007 Jest tests passed, 11 skipped; lint, TypeScript and diff checks passed. Tests cover the one-line slot, sticky type-mode behavior and all-series navigation. A data-preserving Maestro flow was added but not executed; native font fitting and scrolling remain unverified on a device/emulator.

Delivery: PR only, not yet merged or deployed. No backend, pricing-engine, account or collection change. This is separate from quota PR #854.