Rename Wrystr to Vega

Named after Jurij Vega (1754-1802), Slovenian mathematician who made
knowledge accessible through his logarithm tables. Rebrand before
OpenSats application (April 1).

- Product name, window title, identifiers, binary name all renamed
- Cargo package: wrystr -> vega, wrystr_lib -> vega_lib
- PKGBUILD: wrystr -> vega (new AUR package name)
- Release workflow: artifact names, release text updated
- README: new tagline referencing Jurij Vega
- DB migration: auto-renames wrystr.db -> vega.db on first launch
- Keyring service name kept as "wrystr" for backward compatibility
- localStorage keys kept as wrystr_* to preserve existing user data

Pending manual steps:
- Rename GitHub repo hoornet/wrystr -> hoornet/vega
- Create new AUR package vega-git, orphan wrystr-git
- Update local .desktop launcher

src-tauri/tauri.conf.json

@@ -1,8 +1,8 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
-  "productName": "Wrystr",
+  "productName": "Vega",
   "version": "0.9.11",
-  "identifier": "com.hoornet.wrystr",
+  "identifier": "com.hoornet.vega",
   "build": {
     "beforeDevCommand": "npm run dev",
     "devUrl": "http://localhost:1420",
@@ -12,7 +12,7 @@
   "app": {
     "windows": [
       {
-        "title": "Wrystr",
+        "title": "Vega",
         "width": 1200,
         "height": 800,
         "minWidth": 900,
@@ -38,7 +38,7 @@
   "plugins": {
     "updater": {
       "endpoints": [
-        "https://github.com/hoornet/wrystr/releases/latest/download/latest.json"
+        "https://github.com/hoornet/vega/releases/latest/download/latest.json"
       ],
       "pubkey": "dW50cnVzdGVkIGNvbW1lbnQ6IG1pbmlzaWduIHB1YmxpYyBrZXk6IEY5RDJDMzkyOTc1OTI2NTIKUldSU0psbVhrc1BTK2NTcE9ybm1VcG1KU2VicmJUMWd4TmVTMzNYL1M3ZnhCQWIvU2R2V2V3Tm0K",
       "dialog": false