Clean up Flatpak manifest for v2026.2.0

- Update tag to v2026.2.0
- Use SKIP_WASM_BUILD env var instead of build-time package.json patch
- Install metainfo from git source (remove temporary type: file source)
- Fix fix-lockfile.mjs to skip workspace packages
- CI: commit metainfo releases back to app repo, bump permissions to write

flatpak/fix-lockfile.mjs

@@ -47,7 +47,9 @@ let changesMade = false;
 async function fillAllResolved(packages) {
   for (const packagePath in packages) {
     if (packagePath === "") continue;
+    if (!packagePath.includes("node_modules/")) continue;
     const p = packages[packagePath];
+    if (p.link) continue;
     if (!p.inBundle && !p.bundled && (!p.resolved || !p.integrity)) {
       const packageName =
         p.name ||