chore(release): 0.4.8 (versionCode 35) — ship retention improvements (#112)

Bundles the unreleased work sitting on main since v0.4.7:
- Offline demo mode (#108) — value without a server
- First-run clarity + fast-fail connect timeout (#107)
- Directory-browser stuck-state fix (#106)

Version + versionCode bumped and a user-facing changelog added so the owner
can cut the release (tag v0.4.8 / dispatch publish-play-store.yml). Does NOT
itself publish — releasing to production stays an owner action.


Claude-Session: https://claude.ai/code/session_01T12AhSnQVrSxNnvwfCx2z6

Co-authored-by: engineer <engineer@macbookpro.lan>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opencode-ai/mobile",
-  "version": "0.4.7",
+  "version": "0.4.8",
   "private": true,
   "main": "expo-router/entry",
   "scripts": {