Bump to v0.3.0 — instant post/reply feedback

Published notes now appear in the feed immediately. Thread replies
show up without waiting for the relay round-trip. Includes all
v0.2.9 fixes (image paste, sent zaps, reply-to clickable, feed
refresh on login).

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "Wrystr",
-  "version": "0.2.9",
+  "version": "0.3.0",
   "identifier": "com.hoornet.wrystr",
   "build": {
     "beforeDevCommand": "npm run dev",