quest: plan array references from slices and cells

quest/m3/README.md

@@ -51,3 +51,4 @@ memory model for values whose address is reinterpreted, without a consumer.
 - [Browser APIs through wasm-bindgen](/quest/m3/ts-wasm-bindgen/README.md) - web-sys and js-sys imports become direct JS calls, so idiomatic crates such as web-rs's web-codecs translate as stock crates
 - [`if let` of a temporary whose rest drops](/quest/m3/ts-if-let-drop.md) - `if let Some(E::A(x)) = temp()` with a destructor in the rest of `temp` emits TypeScript that type-checks
 - [`u64` wrapping arithmetic in V8](/quest/m3/ts-u64-wrapping.md) - `rs.u64WrappingAdd` and its kin cost near a plain `+` while the value is a safe integer
+- [Array references from slices and cells](/quest/m3/ts-array-ref-conversions.md) - `try_into` of a slice into an array reference, `Cell::as_array_of_cells`, and `identity` of a `&mut [T; N]` lend the array where it is

quest/m3/ts-array-ref-conversions.md

@@ -0,0 +1,20 @@
+# [S] Array references from slices and cells
+
+## Goal
+
+[rust2-ts](/ts/README.md) translates `TryFrom<&mut [T]> for &mut [T; N]` (and its `&[T]`
+twin, as `slice.try_into()` reaches them), `Cell::as_array_of_cells`, and
+`convert::identity` of a `&mut [T; N]`, each lending the array where it is, proven by
+differential tests against native Rust. Today each is an unsupported call.
+
+## Plan
+
+Suggested on [#662](https://github.com/moq-dev/rust2/pull/662), which removed `arrayView`
+and lends parts of arrays where they are: its tests use `first_chunk_mut` in place of these.
+`try_into` of a slice into an array reference is common in parsers. Build on #662's
+`rs.ArraySlice` and slice helpers, adding no new pointer form, per m3's
+[unsafe policy](/quest/m3/README.md).
+
+Decided with the maintainer on 2026-11-07: ✅ plan it, in m3 (from #662's follow-ups).
+
+Public API: the translator's output.