[patricksmill]

Summary

Library selection
  position-based identity + ROM count
    ├── selected cache entry
    ├── selected ROM request
    ├── collection prefetch
    └── persisted selection
App → screen.get_roms_request()

Concentrate platform/manual/smart/virtual selection interpretation and remove separate request methods plus App forwarding. Includes prerequisite saved-selection persistence/restoration changes that were already uncommitted in the checkout; these are required for the behavior covered by the spec. Agent-skill setup files are excluded.

Closes #105
Closes #106

Evidence

• Before: library-browse characterization suite: 17 passed; 0 failed, including overlapping collection IDs and missing versus empty virtual IDs.
  After: the same suite: 17 passed; 0 failed after consolidation.
• After: cargo test --workspace: 439 passed across 28 suites.
• After: cargo fmt --check and both cargo clippy --all-targets --all-features -- -D warnings and cargo clippy --all-targets --no-default-features -- -D warnings completed successfully.
• After: throwaway cargo run -p romm-tui --example selection_smoke printed PASS: filtered smart selection, request identity, saved restoration, neighbor prefetch, metadata reorder and count-change reload. Smoke source removed afterward.
• Independent Standards and Spec reviews of the consolidation against the preserved uncommitted baseline: no findings. These reviews did not treat the prerequisite persistence implementation as new refactor work.
• No live RomM server or interactive-terminal visual check.

Merge Danger

Door: two-way

No cache-format migration. Prerequisite persistence adds an optional, defaulted tui_layout.library_selection configuration field. Existing configuration files remain readable. The library-browse Rust interface replaces get_roms_request_platform / get_roms_request_collection with get_roms_request; in-repo callers are migrated, but external Rust consumers using those methods must migrate too.

Blast Radius: library

Affects library selection, request targeting, prefetch, and saved-selection restoration. Generation guards, cancellation, debounce, and cache-paint policy are unchanged.