feat(installer,web): one canonical bundle per target; robust in-place upgrades; update-check feedback (#142)

Co-authored-by: Yaowei Zheng <hiyouga@buaa.edu.cn>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -45,8 +45,8 @@ jobs:
       - name: Unit tests (vitest)
         run: pnpm test
 
-      - name: Offline bundle and POSIX installer tests
-        run: sh scripts/test-offline-bundles.sh
+      - name: Installer bundle and POSIX installer tests
+        run: sh scripts/test-installer.sh
 
       # The secret is exposed only in this step (step-level env); earlier steps and third-party actions can't see it.
       # The secrets context can't be used in if expressions, so skip inside the shell when it's absent (e.g. forks).
@@ -112,6 +112,6 @@ jobs:
           }
           if ($failed) { exit 1 }
 
-      - name: Windows offline installer tests
+      - name: Windows installer tests
         shell: pwsh
-        run: ./scripts/test-offline-install.ps1
+        run: ./scripts/test-installer.ps1