Reset update-flag on uninstall (#2025)

* Reset update-flag on uninstall

If there is an update available when the extension is uninstalled, the
table will still have the update flag, which makes no sense if it is not
installed.

Example:
```
{
  "pkgName": "eu.kanade.tachiyomi.extension.en.comix",
  "name": "Comix",
  "lang": "en",
  "versionCode": 20,
  "versionName": "1.4.20",
  "iconUrl": "/api/v1/extension/icon/tachiyomi-en.comix-v1.4.20.apk",
  "repo": "<hidden>",
  "isNsfw": true,
  "isInstalled": false,
  "isObsolete": false,
  "hasUpdate": true,
  "__typename": "ExtensionType"
},
```

* Update changelog

CHANGELOG.md

@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - (WebUI) Handle serving non-default webui with "bundled"
 - (WebUI) Wait until WebUI is ready to open in browser
 - (Downloads) Truncate filenames by byte length to prevent "File name too long" IO errors
+- (Extension) Do not indicate an update is available when the extension is not installed
 
 ## [v2.2.2100] + [WebUI: v20260508.01] - 2026-05-08
 

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/extension/Extension.kt

@@ -358,6 +358,7 @@ object Extension {
                 } else {
                     ExtensionTable.update({ ExtensionTable.pkgName eq pkgName }) {
                         it[isInstalled] = false
+                        it[hasUpdate] = false
                     }
                 }