Bump to v0.2.6 — add createUpdaterArtifacts for updater signing

Tauri 2 requires bundle.createUpdaterArtifacts: true to produce .sig
files and updater zip/tar.gz archives. Without it, TAURI_SIGNING_PRIVATE_KEY
is ignored and latest.json is never generated.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "wrystr"
-version = "0.2.5"
+version = "0.2.6"
 description = "Cross-platform Nostr desktop client with Lightning integration"
 authors = ["hoornet"]
 edition = "2021"

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "Wrystr",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "identifier": "com.hoornet.wrystr",
   "build": {
     "beforeDevCommand": "npm run dev",
@@ -26,6 +26,7 @@
   "bundle": {
     "active": true,
     "targets": ["deb", "rpm", "nsis", "msi", "dmg"],
+    "createUpdaterArtifacts": true,
     "icon": [
       "icons/32x32.png",
       "icons/128x128.png",