Add Gitea Actions release workflow + combined VS Code build task

Same pattern as TUI-WM: rolling 'latest' release with linux x64 +
arm64 binaries built on the Pi5 runner.

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

.vscode/tasks.json

@@ -1,6 +1,15 @@
 {
     "version": "2.0.0",
     "tasks": [
+        {
+            "label": "Build alla (Linux + Windows)",
+            "type": "shell",
+            "command": "cargo build --release && cargo build --release --target x86_64-pc-windows-gnu && mkdir -p build/linux build/windows && cp target/release/tui-fm build/linux/tui-fm && cp target/x86_64-pc-windows-gnu/release/tui-fm.exe build/windows/tui-fm.exe && echo 'Done: build/linux/tui-fm + build/windows/tui-fm.exe'",
+            "group": "build",
+            "presentation": { "reveal": "always", "panel": "shared" },
+            "problemMatcher": "$rustc",
+            "detail": "Bygger båda binärerna: Linux (native) + Windows (kräver mingw-w64)"
+        },
         {
             "label": "Build - Linux",
             "type": "shell",