Add nostr+connect QR code flow for bunker login (v0.2.1)

- Add buildNostrConnectUrl() and parseNostrConnectUrl() for nostr+connect:// URLs
- Add BunkerSigner.awaitSignerConnection() for reverse flow (client waits for signer)
- Update BunkerLogin to show QR code that signers like Amber can scan
- Add bunkerLoginWithSigner() to NostrProvider for completing login after scan
- Support both QR scan mode and paste bunker URL mode

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "smesh",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "A user-friendly Nostr client for exploring relay feeds",
   "private": true,
   "type": "module",