Fix Android deployment pipeline and integration tests

- Run integration tests sequentially in Taskfile.yml to avoid port 4190 (ManageSieve) conflict.
- Add ManageSieve listener to Stalwart config for better test coverage.
- Increase Android emulator boot timeout and add software-mode flags (-accel off, -no-boot-anim, -gpu swiftshader_indirect) to accommodate environments without KVM.
- Update LATER.md with notes on software emulation performance.

Taskfile.yml

@@ -200,7 +200,9 @@ tasks:
   _integrations:
     internal: true
     run: once
-    deps: [integration, integration-ui]
+    cmds:
+      - task: integration
+      - task: integration-ui
 
   check:
     desc: Full check suite — unit tests first, then integration (merges coverage), then gate