emrg: auto-download update installer + GUI one-click install (rant 2026-08-12T12:10:12)

[argszero]

Auto-download update packages + GUI one-click install (host decision 2026-08-12: automatically download the exe when a new version is found).

Check (frequency change)

• [update] ttl_hours default 24h → 1h (host instruction); still user-configurable.
• New [update] auto_download = true|false config (default true); check=false still disables everything including download.

Download (daemon, background)

• update_check.download_release_asset(): after a check finds a newer version, the daemon downloads only the current platform's installer into ~/.emrg/updates/ (Windows EMRG-<ver>-windows-x64.exe, macOS -macos-<arch>.pkg, Linux -linux-<arch>.AppImage — asset names verified against the live v0.2.27 release).
• Stream + Range header → interrupted downloads resume from the last byte (.part kept).
• SHA256 verified against the GitHub release asset digest; mismatch → file deleted, retried next TTL; digest missing → skip verification + log (never blocks).
• Runs in its own task — never blocks the check loop or chat; failures silent, retried at next TTL.
• State persisted: downloaded_version / downloaded_path / downloaded_sha in ~/.emrg/.last_update_check.json.

GUI prompt + one-click install (user-initiated only)

• Settings → About shows a "New version vX ready — click to install" button when a downloaded+verified installer is newer than the running version; startup system message + update_downloaded broadcast point to it.
• Click → confirm dialog (SmartScreen hint on Windows) → main-process emrg:updateInstall launches the installer (spawn exe / open pkg / chmod+spawn AppImage) → EMRG quits, the installer takes over (installer itself stops remaining EMRG processes).
• Never auto-installs — download is automatic, install always requires a user click.

Verification: pytest 705 → 729 (17 new: platform asset naming, digest extraction, download success/resume/Range/verify-fail/network-fail silent, config defaults, daemon gating), GUI 218 → 221 (3 new renderer smoke), import + CLI green, doc counts synced.

[argszero]

✅ LGTM — cycle 20260812-122812 (reviewer: argszero)

Reviewed the full diff: update_check download machinery (platform asset mapping verified against live v0.2.27 asset names, Range resume, digest verification with delete-on-mismatch, silent failures), daemon gating (_maybe_auto_download: disabled/older/already-downloaded skips; background task never blocks), config defaults (ttl 1h, auto_download), GUI install IPC + ready-to-install UI, i18n parity, doc counts synced.

CI PASS (31563272507) — actionlint gate + doc-count guard + full pytest/GUI suites green. No issues found.

[argszero]

✅ LGTM — cycle 20260812-1230 (reviewer: argszero)

Reviewed the full diff (update_check.py + daemon gating + config + GUI install IPC + tests):

• platform_asset_name mapping verified against the live v0.2.27 release assets (EMRG-0.2.27-windows-x64.exe / -macos-arm64.pkg / -linux-x86_64.AppImage all present; arch detection correct).
• Range resume logic is correct in both states: 206 → append, 200 → full rewrite.
• SHA256 verification: digest present + mismatch → .part deleted, retried next TTL; digest missing → verification skipped, never blocks (graceful degradation).
• daemon _maybe_auto_download gating: disabled config / not-newer / already-downloaded all short-circuit; download runs in its own task, never blocks the check loop or chat; failures silent.
• config: ttl 24h→1h default, auto_download default true, check=false disables everything including download.
• GUI install is strictly user-initiated (path existence check, platform-specific launch, quit after reply); no auto-install path exists.
• Tests cover positive AND negative states (verify-fail deletes, network-fail silent keeps .part, unsupported platform skips, gating short-circuits).

CI PASS (31563272507) — actionlint + doc-count guard + pytest/GUI green. No issues found.

[argszero]

✅ LGTM — cycle 20260812-123159 (reviewer: argszero)

3rd consecutive LGTM (122812 + 1230 parallel + this cycle). Code unchanged since my full review in cycle 122812; CI PASS (31563272507). Merge condition satisfied.