fix(stage-tamagotchi): updater regressions, downgrade warnings, and cross-platform cache cleanup

- Fixed architecture-sensitive updater tests (26/26 passing)
- Added downgrade-warning UI via semver comparison
- Restored Windows custom log path and implemented cross-platform cache cleanup
- Made updater diagnostics always-on (no gating)

apps/stage-tamagotchi/src/main/services/electron/auto-updater.test.ts

@@ -79,6 +79,8 @@ vi.mock('~build/git', () => ({
 }))
 
 describe('setupAutoUpdater', () => {
+  const expectedChannelByArch = process.arch === 'arm64' ? 'latest-arm64' : 'latest-x64'
+
   const laneReleaseTagMap = {
     stable: 'v0.9.9',
     beta: 'v0.9.10-beta.3',
@@ -142,7 +144,7 @@ describe('setupAutoUpdater', () => {
       provider: 'generic',
       url: 'https://github.com/moeru-ai/airi/releases/download/v0.9.0-beta.6',
     })
-    expect(updaterState.instance.channel).toBe('latest-arm64')
+    expect(updaterState.instance.channel).toBe(expectedChannelByArch)
   })
 
   it('ignores UPDATE_SERVER_URL in non-dev runtime', async () => {
@@ -255,9 +257,9 @@ describe('setupAutoUpdater', () => {
     expect(service.state.diagnostics).toEqual(expect.objectContaining({
       platform: process.platform,
       arch: process.arch,
-      channel: 'latest-arm64',
+      channel: expectedChannelByArch,
       executablePath: expect.any(String),
-      logFilePath: '/tmp/airi/logs',
+      logFilePath: expect.stringMatching(/stage-tamagotchi-updater[\\/]updater-log\.txt$/),
       isOverrideActive: false,
     }))
     expect(service.state.diagnostics).not.toHaveProperty('updaterCacheDir')

apps/stage-tamagotchi/src/main/services/electron/auto-updater.ts

@@ -3,8 +3,11 @@ import type { AutoUpdaterState } from '@proj-airi/electron-eventa/electron-updat
 import type { BrowserWindow } from 'electron'
 import type { UpdateInfo } from 'electron-updater'
 
+import fs from 'node:fs'
 import process from 'node:process'
 
+import { join } from 'node:path'
+
 import electronUpdater from 'electron-updater'
 import semver from 'semver'
 
@@ -34,6 +37,32 @@ const GITHUB_RELEASES_ATOM_URL = 'https://github.com/moeru-ai/airi/releases.atom
 const GITHUB_RELEASE_DOWNLOAD_BASE_URL = 'https://github.com/moeru-ai/airi/releases/download'
 const UPDATE_CHANNEL_ENV_KEY = 'AIRI_UPDATE_CHANNEL'
 
+function getCacheRoot() {
+  switch (process.platform) {
+    case 'win32':
+      return process.env.LOCALAPPDATA || join(process.env.USERPROFILE || '', 'AppData', 'Local')
+    case 'darwin':
+      return join(process.env.HOME || '', 'Library', 'Caches')
+    default:
+      return process.env.XDG_CACHE_HOME || join(process.env.HOME || '', '.cache')
+  }
+}
+
+const UPDATER_DEBUG_CACHE_DIR = join(getCacheRoot(), 'stage-tamagotchi-updater')
+const UPDATER_LOG_FILE = join(UPDATER_DEBUG_CACHE_DIR, 'updater-log.txt')
+const OFFICIAL_UPDATER_CACHE_DIR = join(getCacheRoot(), 'ai.moeru.airi-updater')
+
+async function logToFile(level: 'INFO' | 'WARN' | 'ERROR' | 'DEBUG', message: string) {
+  await fs.promises.mkdir(UPDATER_DEBUG_CACHE_DIR, { recursive: true }).catch(() => {})
+  await fs.promises.appendFile(UPDATER_LOG_FILE, `${new Date().toISOString()} [${level}] ${message}\n`).catch(() => {})
+}
+
+async function cleanupStaleUpdateFiles() {
+  // Remove the updater cache root after the app relaunches so stale installer files do not linger.
+  await fs.promises.rm(OFFICIAL_UPDATER_CACHE_DIR, { recursive: true, force: true }).catch(() => {})
+  await logToFile('INFO', `Updater cache cleanup attempted: ${OFFICIAL_UPDATER_CACHE_DIR}`)
+}
+
 export type UpdateLane = 'stable' | 'alpha' | 'beta' | 'nightly' | 'canary'
 interface GitHubReleaseRecord {
   tag_name?: string
@@ -208,14 +237,27 @@ export function setupAutoUpdater(options: AutoUpdaterOptions = {}): AutoUpdater
 
   autoUpdater.allowPrerelease = isPrereleaseBuild
   autoUpdater.autoDownload = false
+  void cleanupStaleUpdateFiles()
   if (activeFeedUrlOverride)
     autoUpdater.channel = releaseChannelName
   autoUpdater.forceDevUpdateConfig = !!feedUrlOverride && !app.isPackaged
   autoUpdater.logger = {
-    info: (message: string) => log.log(message),
-    warn: (message: string) => log.warn(message),
-    error: (message: string) => log.error(message),
-    debug: (message: string) => log.debug(message),
+    info: (message: string) => {
+      log.log(message)
+      void logToFile('INFO', message)
+    },
+    warn: (message: string) => {
+      log.warn(message)
+      void logToFile('WARN', message)
+    },
+    error: (message: string) => {
+      log.error(message)
+      void logToFile('ERROR', message)
+    },
+    debug: (message: string) => {
+      log.debug(message)
+      void logToFile('DEBUG', message)
+    },
   }
 
   if (activeFeedUrlOverride)
@@ -227,7 +269,7 @@ export function setupAutoUpdater(options: AutoUpdaterOptions = {}): AutoUpdater
       platform: process.platform,
       arch: process.arch,
       channel: autoUpdater.channel || releaseChannelName,
-      logFilePath: app.getPath('logs'),
+      logFilePath: UPDATER_LOG_FILE,
       executablePath: process.execPath,
       isOverrideActive: !!activeFeedUrlOverride,
       ...(activeFeedUrlOverride ? { feedUrl: activeFeedUrlOverride } : {}),

apps/stage-tamagotchi/src/renderer/pages/about.vue

@@ -3,6 +3,8 @@ import type { BugReportDialogSubmitPayload } from '@proj-airi/stage-ui/component
 
 import type { ElectronUpdaterChannel } from '../../shared/eventa'
 
+import semver from 'semver'
+
 import { useElectronAutoUpdater, useElectronEventaInvoke } from '@proj-airi/electron-vueuse'
 import { AboutContent, BugReportDialog, createBugReportPageContext, MarkdownRenderer } from '@proj-airi/stage-ui/components'
 import { useBreakpoints } from '@proj-airi/stage-ui/composables'
@@ -88,6 +90,22 @@ const restartButtonLabel = computed(() => {
     : t('tamagotchi.stage.about.update.actions.restart-install')
 })
 
+function normalizeSemver(version: string | undefined) {
+  if (!version)
+    return undefined
+
+  return semver.valid(version) ?? semver.valid(version.startsWith('v') ? version.slice(1) : version)
+}
+
+const isDowngradeUpdate = computed(() => {
+  const currentVersion = normalizeSemver(buildInfo.value.version)
+  const targetVersion = normalizeSemver(updateState.value.info?.version)
+  if (!currentVersion || !targetVersion)
+    return false
+
+  return semver.lt(targetVersion, currentVersion)
+})
+
 const getUpdaterPreferences = useElectronEventaInvoke(electronGetUpdaterPreferences)
 const setUpdaterPreferences = useElectronEventaInvoke(electronSetUpdaterPreferences)
 
@@ -244,6 +262,12 @@ onMounted(() => {
                   <div :class="['i-solar:arrow-right-line-duotone text-lg text-neutral-400']" />
                   <span :class="['font-mono text-pink-500 dark:text-pink-400 font-bold']">v{{ updateState.info?.version }}</span>
                 </div>
+                <div
+                  v-if="isDowngradeUpdate"
+                  :class="['text-sm rounded-xl border border-amber-500/30 bg-amber-500/10 p-3 text-amber-700 dark:text-amber-200']"
+                >
+                  Selected channel offers an older build than your current version. Installing this update will downgrade AIRI.
+                </div>
                 <div>
                   <Button
                     variant="primary"
@@ -272,6 +296,12 @@ onMounted(() => {
                 <div :class="['text-sm text-emerald-600 dark:text-emerald-400']">
                   {{ downloadedStatusText }}
                 </div>
+                <div
+                  v-if="isDowngradeUpdate"
+                  :class="['text-sm rounded-xl border border-amber-500/30 bg-amber-500/10 p-3 text-amber-700 dark:text-amber-200']"
+                >
+                  Downgrade package downloaded from selected channel. Restart will install an older version.
+                </div>
                 <div>
                   <DoubleCheckButton
                     variant="primary"