me-web? skeleton: Avalonia 12 app, server, packaging and CI

The first screen (online or not, a Check button, every language with a
draft notice), the desktop and Android heads, the server's /api/info and
/api/ip, a release tool that builds deb, rpm, a Windows exe, macOS zips,
a signed APK and the server, and the Gitea workflows that run it. Rules
adapted from passolo; AGPL-3.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

.gitea/workflows/build.yml

@@ -0,0 +1,15 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    name: Desktop, server and tools
+    runs-on: nuvola
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build
+        run: tools/ci.sh