Cleanup: drop pluralize re-export wrappers, dedup the noun-check constant

Callers now import `pluralize`/`pluralize_with` from `crate::pluralize` (Rust) and `$lib/utils/pluralize` (TS). `column_meta` and `selection-info-utils` only re-exported them; the wrappers earned their keep during the initial sweep but become dead weight once the consumers are migrated.

- Rust: `virtual_listing.rs` and `log.rs` import directly from `crate::pluralize`; `column_meta.rs` drops the `pub use` line and its duplicate test (the canonical tests live in `pluralize.rs`).
- TS: `SelectionInfo.svelte`, `FullList.svelte`, `BriefList.svelte` import from `$lib/utils/pluralize`; `selection-info-utils.ts` drops the `export { pluralize }` line and `selection-info-utils.test.ts` drops the duplicate `pluralize` tests (the canonical tests live in `pluralize.test.ts`).
- CLAUDE.md updates: the column_meta and selection-info-utils entries point at `crate::pluralize` / `$lib/utils/pluralize` instead.

Also drops the duplicate `allowPluralizeNounCommentTs` const in `scripts/check/checks/pluralize-noun.go`: same string as `AllowPluralizeNounComment`, and both Rust and TS use `//` for line comments so one marker covers everything.

Author: vdavid