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/scripts/prepare.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+version=$(sed -n 's:.*<Version>\(.*\)</Version>.*:\1:p' Directory.Build.props | head -n 1)
+if [ "$GITHUB_REF_TYPE" = "tag" ] && [ "$GITHUB_REF_NAME" != "v$version" ]; then
+  echo "::error::tag $GITHUB_REF_NAME does not match Version $version in Directory.Build.props"
+  exit 1
+fi
+echo "VERSION=$version" >> "$GITHUB_ENV"
+echo "COMMIT=$(echo "$GITHUB_SHA" | cut -c1-8)" >> "$GITHUB_ENV"
+keep="$HOME/.cache/meweb"
+for dir in tools/cache tools/jdk tools/packaging tools/android-sdk; do
+  mkdir -p "$keep/$dir"
+  rm -rf "$dir"
+  ln -s "$keep/$dir" "$dir"
+done
+rm -rf releases dist
+echo "version $version, tools cached in $keep"