gitpic: Instructions file for Codex

Repository Guidelines

Project Structure & Module Organization

gitpic is a Rust CLI. Source lives in src/:

• main.rs — entry point, subcommand dispatch, exit codes.
• cli.rs — clap argument/subcommand definitions.
• config.rs — config model + XDG path resolution (~/.config/gitpic/config.toml).
• auth.rs — the credential: reads/writes the 0600 auth.toml that gitpic auth login produces, and is the only source there is. No secret is held in Config.
• oauth.rs — GitHub device flow: the wire protocol behind gitpic auth login.
• github.rs — GitHub Contents API client (upload, dedup, health checks).
• naming.rs, link.rs, imageproc.rs, output.rs, error.rs — path/hash, URL/markdown, compression, human/JSON output, error types.
• history.rs — the upload log the app's 历史 pane reads.
• release.rs — the update check behind gitpic update check: version parsing and comparison, the releases/latest fetch, and the release's assets (name, size, download URL, GitHub's digest) that the app installs an update from. The origin is a compile-time constant on purpose, pinned by a test — its text is rendered inside GitPic's own window, so nothing configurable may choose it, and download URLs come from the API rather than a template for the same reason.
• install_source.rs — which of the three ways this binary was installed (inside GitPic.app, cargo install, or unknown), so gitpic update prints the one upgrade command that install actually wants instead of two to choose between. Canonicalises current_exe() first: the app links ~/.local/bin/gitpic into the bundle, so the commonest install of all is invoked through a symlink, and on Apple platforms the un-canonicalised path is that symlink — which classifies it as neither an app nor a cargo bin and prints "download it again" for the one install that updates itself.
• testutil.rs — #[cfg(test)] only: the loopback stub server, a canned response, and the request reader shared by github's and release's tests. One sock.read is not a whole request; the module says what that cost twice.
• commands/ — one module per action (upload, auth_cmd, repos, branches, doctor, list, config_cmd, completion, skill, update).