emrg: GUI upgrade banner — show version range from→to (rant 2026-08-21T12:44:34)

[argszero]

Summary

Fixes rant 2026-08-21T12:44:34 (banner item) — the GUI upgrade-complete banner now shows the version range instead of only the target version: "EMRG 已从 0.2.57 升级到 0.2.61，重启后生效".

Changes

• emrg/server/daemon.py — new _previous_installed_version() reading ~/.emrg/install/previous-version.txt; pong payload now carries both current_version and previous_version (raw data only, zero judgment).
• emrg/server/prompts/upgrade_prompt.j2 — instructs the upgrade agent to copy the current version.txt content to previous-version.txt before overwriting it (and to remove a stale previous-version.txt on first install).
• emrg/gui/main.js — init + status pushes forward previous_version from the pong.
• emrg/gui/renderer/js/app.js — maybeShowUpgradeBanner(currentVersion, previousVersion) shows the from→to message when a previous version is available (and differs), falling back to the old single-version message otherwise. state.previousVersion initialized from init and updated on pong.
• emrg/gui/renderer/js/i18n.js — new app.upgradeBannerMsgFromTo key (zh + en).
• emrg/gui/test/renderer.smoke.test.js — banner test extended to assert the from→to text.
• tests/test_daemon.py — new test_pong_includes_previous_version (positive + missing-file + pong payload).
• Agent.md — Python count 988→989.

Verification

• Python: uv run pytest tests/ — 988 passed + 1 skipped (989 collected), incl. the new pong test
• GUI: npm test — 255 tests, 247 pass, 8 skipped, 0 fail
• node --check + import + CLI OK

[argszero]

✅ LGTM — cycle

Fresh review of the upgrade-banner range change (rant 2026-08-21T12:44:34):

• daemon: _previous_installed_version() reads ~/.emrg/install/previous-version.txt (raw data, "" when missing — dev/first-install safe); pong carries both current_version and previous_version.
• upgrade_prompt.j2: agent instructed to copy current version to previous-version.txt before overwriting version.txt (and clear stale record on first install) — closes the persistence loop so even a fresh GUI launch shows the range.
• GUI: maybeShowUpgradeBanner(current, previous) shows from→to when previous differs, falls back to the old single-version message otherwise; state.previousVersion threaded from init + pong. i18n added for both zh/en.
• Tests: banner test asserts "0.2.57 → 0.2.61" text; new daemon pong test covers positive + missing-file + payload. Agent.md Python 988→989.
• Verified: Python pytest 988 passed + 1 skipped, GUI npm test 255 (247+8), import + CLI OK. CI test + test-windows PASS.

1/3.

[pm25coder]

Independent test report (Contributor, pm25coder):

[argszero]

✅ LGTM — cycle

2nd review (head cc6e14c, CI test + test-windows PASS on run 32449902478):

• Fresh local verification: Python pytest 988 passed + 1 skipped (989 collected, matches Agent.md), GUI npm test 255 (247 pass / 0 fail / 8 skipped), import + CLI OK.
• daemon: _previous_installed_version() reads ~/.emrg/install/previous-version.txt with OSError/ValueError fallback to "" (dev/first-install safe); pong now carries previous_version alongside current_version.
• upgrade_prompt.j2: agent copies the pre-overwrite version into previous-version.txt before writing version.txt, and clears stale record on first install — closes the persistence loop so the banner range survives a fresh GUI launch.
• GUI: maybeShowUpgradeBanner(current, previous) renders from→to when previous differs, falls back to the single-version message otherwise; state.previousVersion threaded from init + status events. i18n zh/en keys added.
• Tests: banner smoke asserts both "0.2.57" and "0.2.61" in the message; new daemon pong test covers previous-version payload. Both positive/negative paths exercised.

2/3. Note: master advanced since this PR's base (#912 merged) — the final merge will need the resolved tree re-verified, but no code conflicts expected (Agent.md Python line vs #912's GUI line merge cleanly).

[argszero]

✅ LGTM — cycle

3rd consecutive review (head ec88809 — conflict-resolved merge of master, CI test + test-windows PASS on the resolved tree):

• Fresh local verification on the merged tree: pytest 988 passed + 1 skipped (989 collected, matches Agent.md), import + CLI OK.
• Conflict resolution: #912's heartbeat merge touched main.js + Agent.md; merged tree has both #912 heartbeat and #913 banner changes; Agent.md now Python 989 / GUI 256 (127 renderer smoke); no conflict markers left.
• Code (from earlier review, unchanged in substance): daemon _previous_installed_version() reads ~/.emrg/install/previous-version.txt (raw data, '' when missing — dev/first-install safe); upgrade_prompt.j2 copies version.txt → previous-version.txt before overwrite; pong carries current + previous version; GUI banner shows from→to when previous version differs, falls back to single-version message; i18n key zh+en.

3/3.