fix(store): rustdoc hygiene — the wave-5 module doc's private-item links de-linked

The wave-5 landing introduced four rustdoc warnings (cargo doc was no
longer clean): the public store module doc's new intra-doc links
resolved to crate-internal items — AnyCursor, KvCursor, LargeCursor,
and the store-core ensure_gc_schema_at_construction. The names are
prose now (no links): private items never resolve from public docs.

Verified: cargo doc --no-deps zero warnings; cargo clippy --all-targets
-- -D warnings green; cargo fmt --check green. Found by the wave-5
review gate (tasks/review-wave-5.md PGLO-1).

src/store.rs

@@ -91,9 +91,9 @@
 //!   returns the pinned `(len, stream)` shape as
 //!   `Option<(u64, Blob)>` (store-api.md §Read path) — [`Blob`] is a
 //!   bounded, re-entrant windowed reader over the crate-internal
-//!   [`AnyCursor`], which dispatches the engine cursor bodies by tier
+//!   `AnyCursor`, which dispatches the engine cursor bodies by tier
-//!   — the kv materializing bodies behind [`KvCursor`] on the one
+//!   — the kv materializing bodies behind `KvCursor` on the one
-//!   arm, the large streaming bodies behind [`LargeCursor`] on the
+//!   arm, the large streaming bodies behind `LargeCursor` on the
 //!   other (both sub-enums the recorded design points). Windowed
 //!   reads are the uniform stream shape across
 //!   tiers; no chunk-iterator machinery was adopted — the cursor
@@ -239,7 +239,7 @@
 //! kv engines — host: their constructors run the GC schema's
 //! engine-neutral call (`ensure_gc_schema` on the `EngineWindowState`
 //! seam) at construction, dispatched off the engine representation
-//! ([`ensure_gc_schema_at_construction`]). Pg-lo's dormancy landed
+//! (`ensure_gc_schema_at_construction`). Pg-lo's dormancy landed
 //! with the wave-5 wiring: on a dual-SQL instance (kv =
 //! sqlite/postgres + large = pg-lo) the kv host's call runs and
 //! pg-lo's window clauses are **dormant** (the pg-lo schema carries