0e5afe0b01
Triggered by a Telegram report from a Chinese user trying to deploy DeepSeek TUI on a HarmonyOS ARM64 thin-and-light: `npm i -g deepseek-tui` exited with `Unsupported architecture: arm64 on platform linux` because v0.8.7 only published x64 Linux artifacts. They worked around it with `cargo install`, but the README never documented that path for ARM users. This PR closes that gap on three layers: - **Release workflow** — add `aarch64-unknown-linux-gnu` to the build matrix using GitHub's `ubuntu-24.04-arm` runner. v0.8.8 will publish `deepseek-linux-arm64` and `deepseek-tui-linux-arm64` alongside the existing x64/macOS/Windows assets, plus add the row to the Release body's manual-download table. - **npm wrapper** — uncomment the linux/arm64 row in `ASSET_MATRIX`, rewrite the `Unsupported architecture/platform` error to print the full `cargo install deepseek-tui-cli deepseek-tui --locked` recipe and link to docs/INSTALL.md, and add `DEEPSEEK_TUI_OPTIONAL_INSTALL=1` so CI matrices that include unsupported platforms can keep running without a binary. - **Docs** — new docs/INSTALL.md covering every supported platform, prebuilt vs. cargo install vs. manual download, cross-compiling x64 -> ARM64 with `cross` or `gcc-aarch64-linux-gnu`, China mirror setup, and a troubleshooting section for the common arm64, MISSING_COMPANION_BINARY, and self-update arch-mapping (#503) errors. README and README.zh-CN now have an explicit Linux ARM64 quickstart pointing at `cargo install` for v0.8.7 today and `npm i -g` for v0.8.8+; the v0.8.7 known-issue block is updated to mention both #503 and the missing arm64 prebuilt. https://claude.ai/code/session_01Fg1FKMtDxVnC4pp6bNBRCS