local activity storage and convert page fixes

- Replace rdp dependency with inline pure-Python RDP implementation
    so the bincio wheel runs in Pyodide (no pure-Python wheel existed for rdp)
  - Fix convert page script: remove define:vars so Vite bundles it and
    TypeScript imports (localstore, format) work correctly
  - Rename wheel to proper PEP 427 filename (bincio-0.1.0-py3-none-any.whl)
  - Use en-GB date format on convert result, consistent with the feed
  - Add /activity/local/ page + LocalActivityDetail for IDB-only activities;
    feed links local activities there instead of the SSG route
  - Fix getStaticPaths: try public/data symlink as fallback, never crash on
    missing index.json
  - Fix ActivityDetail.onMount: load detail even when detail_url is absent
    so locally converted activities show map and charts
  - Derive track_url and detail_url from id in toSummary() since they are
    not present in the detail JSON
  - Reload on bfcache restore (pageshow) so client:only components re-mount
    after back navigation

site/src/pages/activity/[id].astro

@@ -6,17 +6,25 @@ import ActivityDetail from '../../components/ActivityDetail.svelte';
 import type { BASIndex, ActivitySummary, AthleteZones } from '../../lib/types';
 
 export async function getStaticPaths() {
-  const dataDir = process.env.BINCIO_DATA_DIR
-    ?? resolve(process.cwd(), '..', 'bincio_data');
-  const raw = readFileSync(join(dataDir, 'index.json'), 'utf-8');
-  const index: BASIndex = JSON.parse(raw);
+  try {
+    const candidates = [
+      process.env.BINCIO_DATA_DIR,
+      resolve(process.cwd(), 'public', 'data'),  // symlinked by `bincio render`
+      resolve(process.cwd(), '..', 'bincio_data'),
+    ].filter(Boolean) as string[];
+    const dataDir = candidates.find(d => { try { readFileSync(join(d, 'index.json')); return true; } catch { return false; } })!;
+    const raw = readFileSync(join(dataDir, 'index.json'), 'utf-8');
+    const index: BASIndex = JSON.parse(raw);
 
-  return index.activities
-    .filter(a => a.privacy !== 'private' && a.id)
-    .map(a => ({
-      params: { id: a.id },
-      props: { activity: a, athlete: index.owner.athlete ?? null },
-    }));
+    return index.activities
+      .filter(a => a.privacy !== 'private' && a.id)
+      .map(a => ({
+        params: { id: a.id },
+        props: { activity: a, athlete: index.owner.athlete ?? null },
+      }));
+  } catch {
+    return [];
+  }
 }
 
 const { activity, athlete } = Astro.props as { activity: ActivitySummary; athlete: AthleteZones | null };

site/src/pages/activity/local/index.astro

@@ -0,0 +1,8 @@
+---
+import Base from '../../../layouts/Base.astro';
+import LocalActivityDetail from '../../../components/LocalActivityDetail.svelte';
+const base = import.meta.env.BASE_URL;
+---
+<Base title="Activity — BincioActivity">
+  <LocalActivityDetail {base} client:only="svelte" />
+</Base>