Merge pull request 'publish android' (#13) from build into main

Reviewed-on: https://forgejo.pschneider.fr/notazof/yavsc/pulls/13

build

refacto blogPost

ci: publish APK to GitHub release on v* tag

Adds a publish-release job that triggers only on tag pushes (refs/tags/v*).
It reuses the APK artifact uploaded by apk-deploy, publishes a GitHub
release via softprops/action-gh-release, and attaches the APK.

Result: a stable permalink to the latest APK at
  https://github.com/<owner>/<repo>/releases/latest/download/PostIt.Android.apk

Localisation

Just post one, at least

tests: feed WebServerFixture a Smtp config so Authenticate fires

The EMaillingTests.SendEMailSynchrone smoke test asserts the
recording fake observed this exact call sequence on a successful
send:

  Connect, Authenticate, Send, Disconnect

MailSender.SendEmailAsync only calls Authenticate when
smtpSettings.UserName is non-null (src/Yavsc.Server/Services/
MailSender.cs line 89). WebServerFixture built the host without
a Smtp config — so UserName resolved to null, Authenticate was
skipped, and the recording captured only:

  Connect, Send, Disconnect

Pre-existing breakage, not introduced by recent work; the
fixture had been loading from .env indirectly (probably never,
or before a refactor that stopped doing so).

Feed the test host a fake SMTP config via the same
AddInMemoryCollection the fixture already uses for
ConnectionStrings:

  Smtp:Host     = smtp.test.local
  Smtp:Port     = 465
  Smtp:UserName = test-user
  Smtp:Password = test-pass

UserName non-null means MailSender now exercises the Authenticate
branch, which the recording captures. Tests in the Yavsc.Org.Tests
suite: 21/21 green (was 20/21 with SendEMailSynchrone failing).