feat(notify): in-app notifications with the app's own sound

The system balloon carries the OS notification sound, which does not belong to
this app, and it only fired while the window was out of focus — with the app
focused nothing appeared at all.

Notifications now surface inside the window, carry the same synthesised timbre
as the rest of the app's sounds, and clicking one opens the channel. The native
balloon is kept for when the window is not visible, since an in-app card
nobody can see is no notification, but it is now silent: the app plays its own
effect instead.

A focused window is notified only about other channels — announcing the
conversation someone is already reading is noise.

Also fixes the Gitea publish cleanup, which silently deleted nothing: it
interpolated an Actions expression inside a bash , and when the pattern
did not match, the loop passed over every asset. The release ended with two
latest.yml files and the updater served the older one, reporting 1.1.0 as
current — an update that exists but is never offered, with no error anywhere.
The filter is plain bash now, logs what it found, and the job fails if more
than one latest.yml survives.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.github/workflows/publish-gitea.yml

@@ -153,14 +153,31 @@ jobs:
 
           # Remove só os anexos que esta plataforma vai repor, para os dois jobs
           # não apagarem o trabalho um do outro.
+          #
+          # Padrão montado em bash puro: a versão anterior interpolava uma
+          # expressão do Actions dentro de um `case`, e quando ela não casou o
+          # laço passou em silêncio — a release ficou com dois latest.yml e o
+          # updater serviu o antigo, dizendo que a versão nova não existia.
+          if [ "${RUNNER_OS:-}" = "Windows" ]; then
+            MINE='\.exe$|^latest\.yml$'
+          else
+            MINE='\.AppImage$|\.deb$|^latest-linux\.yml$'
+          fi
+
           R=$(api GET "/releases/$ID/assets")
-          if [ "$(code "$R")" = "200" ]; then
-            body "$R" | jq -r '.[] | "\(.id) \(.name)"' | while read -r aid aname; do
-              case "$aname" in
-                ${{ runner.os == 'Windows' && '*.exe|latest.yml' || '*.AppImage|*.deb|latest-linux.yml' }})
-                  echo "removendo anexo antigo: $aname"
-                  api DELETE "/releases/$ID/assets/$aid" > /dev/null ;;
-              esac
+          if [ "$(code "$R")" != "200" ]; then
+            echo "::error::não foi possível listar os anexos — HTTP $(code "$R"): $(body "$R")"
+            exit 1
+          fi
+
+          OLD=$(body "$R" | jq -r '.[] | "\(.id) \(.name)"' | grep -E " .*($MINE)" || true)
+          echo "anexos desta plataforma já na release: $(printf '%s' "$OLD" | grep -c . || true)"
+          if [ -n "$OLD" ]; then
+            printf '%s\n' "$OLD" | while read -r aid aname; do
+              [ -n "$aid" ] || continue
+              echo "removendo anexo antigo: $aname"
+              D=$(api DELETE "/releases/$ID/assets/$aid")
+              [ "$(code "$D")" = "204" ] || echo "::warning::falha ao remover $aname — HTTP $(code "$D")"
             done
           fi
 
@@ -181,3 +198,16 @@ jobs:
           done
           [ "$sent" -gt 0 ] || { echo "::error::o build não produziu instaladores"; exit 1; }
           echo "$sent arquivo(s) publicados"
+
+          # O updater busca latest.yml pelo nome. Duas cópias com o mesmo nome
+          # fazem o Gitea servir a mais antiga, e a atualização deixa de ser
+          # oferecida — sem erro em lugar nenhum. Falha aqui em vez de publicar
+          # uma release que parece boa e não atualiza.
+          if [ "${RUNNER_OS:-}" = "Windows" ]; then
+            R=$(api GET "/releases/$ID/assets")
+            DUP=$(body "$R" | jq -r '[.[] | select(.name == "latest.yml")] | length')
+            if [ "$DUP" != "1" ]; then
+              echo "::error::a release tem $DUP cópias de latest.yml — o updater serviria a errada"
+              exit 1
+            fi
+            echo "latest.yml: 1 cópia, como esperado"