feat: implement offer pooling for multi-connection services

- Add OfferPool class for managing multiple offers with auto-refill polling
- Add ServicePool class for orchestrating pooled connections and connection registry
- Modify exposeService() to support poolSize parameter (backward compatible)
- Add discovery API with service resolution and online status checking
- Add username claiming with Ed25519 signatures and TTL-based expiry
- Fix TypeScript import errors (RondevuPeer default export)
- Fix RondevuPeer instantiation to use RondevuOffers instance
- Fix peer.answer() calls to include required PeerOptions parameter
- Fix Ed25519 API call (randomSecretKey vs randomPrivateKey)
- Remove bloom filter (V1 legacy code)
- Update version to 0.8.0
- Document pooling feature and new APIs in README

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

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

package-lock.json

@@ -1,20 +1,30 @@
 {
   "name": "@xtr-dev/rondevu-client",
-  "version": "0.7.11",
+  "version": "0.7.12",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@xtr-dev/rondevu-client",
-      "version": "0.7.11",
+      "version": "0.7.12",
       "license": "MIT",
       "dependencies": {
+        "@noble/ed25519": "^3.0.0",
         "@xtr-dev/rondevu-client": "^0.5.1"
       },
       "devDependencies": {
         "typescript": "^5.9.3"
       }
     },
+    "node_modules/@noble/ed25519": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/@noble/ed25519/-/ed25519-3.0.0.tgz",
+      "integrity": "sha512-QyteqMNm0GLqfa5SoYbSC3+Pvykwpn95Zgth4MFVSMKBB75ELl9tX1LAVsN4c3HXOrakHsF2gL4zWDAYCcsnzg==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
     "node_modules/@xtr-dev/rondevu-client": {
       "version": "0.5.1",
       "resolved": "https://registry.npmjs.org/@xtr-dev/rondevu-client/-/rondevu-client-0.5.1.tgz",