fix: pass wheel filename through extraction chain to fix micropip install

micropip requires the full PEP 427 wheel filename (name-version-py-abi-plat.whl)
— writing the file as bincio.whl caused InvalidWheelFilename. The wheel URL from
/api/wheel/version now provides the basename; it flows through fetchWheelBase64 →
extractFile → WebView where the file is written with the correct name and
_wheel_path is set as a Pyodide global before PY_INSTALL_WHEEL runs.

mobile/app/(tabs)/import.tsx

@@ -97,12 +97,13 @@ export default function ImportScreen() {
     // allows local-network HTTP (NSAllowsLocalNetworking=true in Info.plist).
     const instanceUrl = await getInstanceUrl(dbCtx);
     setState({ status: 'loading', msg: 'Fetching Bincio engine…' });
-    const wheelBase64 = await fetchWheelBase64(instanceUrl);
+    const { base64: wheelBase64, filename: wheelFilename } = await fetchWheelBase64(instanceUrl);
 
     const result = await extractFile(
       name,
       base64,
       wheelBase64,
+      wheelFilename,
       (msg) => setState({ status: 'loading', msg }),
     );
 
@@ -215,21 +216,25 @@ async function getInstanceUrl(db: ReturnType<typeof useSQLiteContext>): Promise<
 }
 
 // In-memory cache so repeated imports in one session don't re-download the wheel.
-let _cachedWheelBase64: string | null = null;
+let _cachedWheel: { base64: string; filename: string } | null = null;
 
-async function fetchWheelBase64(instanceUrl: string): Promise<string> {
+async function fetchWheelBase64(instanceUrl: string): Promise<{ base64: string; filename: string }> {
-  if (_cachedWheelBase64) return _cachedWheelBase64;
+  if (_cachedWheel) return _cachedWheel;
 
   const base = instanceUrl || 'https://bincio.org';
 
   // Ask the instance for the canonical wheel URL (handles both dev and prod layouts).
   let wheelUrl = `${base}/api/wheel/download`;
+  let wheelFilename = 'bincio-0.1.0-py3-none-any.whl';
   try {
     const vr = await fetch(`${base}/api/wheel/version`, { signal: AbortSignal.timeout(5000) });
     if (vr.ok) {
       const d = await vr.json() as { api_url?: string; url?: string };
       const path = d.api_url ?? d.url ?? '/api/wheel/download';
       wheelUrl = path.startsWith('http') ? path : `${base}${path}`;
+      // Extract the filename from the URL path (last segment after final /)
+      const urlBasename = wheelUrl.split('/').pop() ?? '';
+      if (urlBasename.endsWith('.whl')) wheelFilename = urlBasename;
     }
   } catch {}
 
@@ -237,8 +242,8 @@ async function fetchWheelBase64(instanceUrl: string): Promise<string> {
   const resp = await fetch(wheelUrl);
   if (!resp.ok) throw new Error(`Could not download Bincio engine (${resp.status}). Is the instance running?`);
   const buf = await resp.arrayBuffer();
-  _cachedWheelBase64 = arrayBufferToBase64(buf);
+  _cachedWheel = { base64: arrayBufferToBase64(buf), filename: wheelFilename };
-  return _cachedWheelBase64;
+  return _cachedWheel;
 }
 
 function arrayBufferToBase64(buf: ArrayBuffer): string {

mobile/extraction/PyodideWebView.tsx

@@ -13,9 +13,10 @@ const PY_INSTALL_PACKAGES = [
 // emfs:// is Pyodide's Emscripten-FS URL scheme — the only reliable way to
 // install a wheel from bytes without an http/https URL (blob: URLs are not
 // recognised by micropip and cause an InvalidRequirement parse error).
+// _wheel_path is set as a Pyodide global before this runs.
 const PY_INSTALL_WHEEL = [
   'import micropip',
-  'await micropip.install("emfs:///tmp/bincio.whl", deps=False)',
+  'await micropip.install("emfs://" + _wheel_path, deps=False)',
 ].join('\n');
 
 const PY_EXTRACT = [
@@ -94,6 +95,7 @@ window._bincioExtract = async function(params) {
   var filename      = params.filename;
   var base64        = params.base64;
   var wheelBase64   = params.wheelBase64;    // pre-fetched by React Native (avoids ATS/HTTP issues)
+  var wheelFilename = params.wheelFilename;  // e.g. "bincio-0.1.0-py3-none-any.whl"
 
   function post(m) { _post(Object.assign({}, m, { reqId: reqId })); }
 
@@ -118,7 +120,9 @@ window._bincioExtract = async function(params) {
     if (!wheelReady) {
       post({ type: 'progress', msg: 'Loading Bincio…' });
       var wheelBytes = Uint8Array.from(atob(wheelBase64), function(c) { return c.charCodeAt(0); });
-      pyodide.FS.writeFile('/tmp/bincio.whl', wheelBytes);
+      var wheelPath  = '/tmp/' + wheelFilename;
+      pyodide.FS.writeFile(wheelPath, wheelBytes);
+      pyodide.globals.set('_wheel_path', wheelPath);
       await pyodide.runPythonAsync(_PY_INSTALL_WHEEL);
       wheelReady = true;
     }

mobile/extraction/extractActivity.ts

@@ -60,6 +60,7 @@ export function extractFile(
   filename: string,
   base64: string,
   wheelBase64: string,
+  wheelFilename: string,
   onStatus: (msg: string) => void = () => {},
 ): Promise<ExtractionResult> {
   if (isExtracting) return Promise.reject(new Error('Another extraction is already in progress'));
@@ -69,7 +70,7 @@ export function extractFile(
 
   isExtracting = true;
   const reqId = String(++reqCounter);
-  const args = JSON.stringify({ reqId, filename, base64, wheelBase64 });
+  const args = JSON.stringify({ reqId, filename, base64, wheelBase64, wheelFilename });
 
   return new Promise<ExtractionResult>((resolve, reject) => {
     pending.set(reqId, {