Automatic app updates

[mattdjenkinson]

Overview

This branch adds stable vs beta update streams aligned with GitHub releases, extends the auto-update path with pending install and platform-specific apply/restart, improves Settings and toast UX, and updates CI so beta tags publish as GitHub pre-releases without touching Homebrew.

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Library (lib)

Update channels

• Introduces UpdateChannel (stable | beta) with serde (lowercase).
• Default channel is inferred from the running build’s CARGO_PKG_VERSION: a semver pre-release segment (any - after an optional v prefix) ⇒ beta; otherwise stable.
• UpdateSettings now includes:
  • update_channel
  • pending_install_path / pending_update_version (install on next launch / display)
  • Default check interval changed from 12h to 6h

GitHub releases API

• Fetches up to 100 releases (per_page=100).
• Deserializes draft and prerelease on each release.
• select_release_for_channel: picks the newest eligible release that has a platform asset and is semver-newer than the installed version.
  • Stable: non-draft, not rolling, not GitHub pre-release, tag without - in the version part (after v).
  • Beta: GitHub pre-releases or hyphenated tags; does not offer plain stable releases to beta users.
• Refactors asset lookup with try_find_platform_asset / find_platform_asset.

Install / restart

• has_pending_install, get_pending_install_path, set_pending_install, clear_pending_install, get_pending_update_version.
• apply_update / apply_update_static: macOS (DMG → mount, rsync to /Applications), Windows (NSIS /S), Linux (replace AppImage in place).
• spawn_install_and_restart: detached helper (shell on Unix, PowerShell on Windows) that waits for the app to exit, runs install, then restarts.
• DATUM_UPDATE_FAKE=1: skips real install for local UI/testing.

Other

• Repo::from_path for paths used without opening the repo.
• Re-exports UpdateChannel from lib.
• Unit tests for channel inference and release selection (stable vs beta, drafts, hyphen tags, assets, ordering).

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UI (ui)

• Settings: stable / beta channel control, persisted via update settings; selected channel shows a check icon.
• Update toast: both actions dismiss the toast; Install now clears in-flight update state consistently with Later while still triggering install.
• Tailwind: toast container/list/item styles, success/error/warning/info variants, and supporting utilities (text-lg, ease-out, positioning, pb-48, etc.).
• check.svg asset and icon wiring.

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GitHub Actions

bundle.yml (tag push v*)

• Classifies tag as beta if the version (after stripping v) contains -.
• Beta ⇒ prerelease: true, make_latest: false; stable ⇒ prerelease: false, make_latest: true.
• update-homebrew runs only for non–pre-release tags so the cask is not updated from beta builds.

manual-release.yml

• Same tag-based beta vs stable classification for prerelease.
• make_latest remains false for manual runs (unchanged policy).
• Input description documents stable vs beta tag shape.

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README

• Shortened to download (including Homebrew), development prerequisites, and minimal run instructions for GUI and CLI.