git:20261004.4bb7222 to git:20261004.1dfa507

2 added, 1 removed. Audit A to A.

---

description: Safe decoding of file text ingress

globs:

- "internal/textenc/**/*.go"

- - "internal/platform/*encoding*.go"

+ - "internal/platform/output_other.go"

+ - "internal/platform/output_windows.go"

- "internal/tools/fs/read*.go"

- "internal/session/promptfiles.go"

- "internal/session/mentions.go"

- "internal/devinfake/**/*.go"

alwaysApply: false

---

# Text encoding ingress

- File text ingress returns valid UTF-8 or a binary or undecodable error through `textenc.DecodeToUTF8`; never cast arbitrary bytes to text.

- Check valid UTF-8 before the NUL or binary gate, and detect BOM-less UTF-16 separately.

- Route known images and binaries through their dedicated path before provider text handling.

- Do not choose a charset only from a chardet name or confidence. Preserve the concentrated non-ASCII second pass and guarded system ANSI preference.

- Keep the Devin fake's invalid-UTF8 rejection.

- This policy excludes grep and command byte semantics.

- Heuristic changes require Windows tests, `make check-windows`, and `make lint-windows`.