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

.claude/projects/-home-hoornet-projects-wrystr/memory/project_podcast_idea.md

@@ -0,0 +1,13 @@
+---
+name: Podcast playback idea
+description: Background audio podcast playback in Wrystr, inspired by Fountain.fm's Nostr integration
+type: project
+---
+
+**Idea: In-app podcast listening for Nostr-native podcasts**
+
+Fountain.fm publishes podcast episodes on Nostr. Wrystr could support playback the other way around — discover and listen to podcasts from within Wrystr.
+
+**Why:** Desktop app is perfect for background audio. Podcast + Nostr is a growing niche (Fountain.fm, Wavlake). Value4Value streaming sats would tie into existing NWC/zap infrastructure. Differentiator vs other Nostr clients.
+
+**How to apply:** When scoping future media features, consider this alongside the video/media feed idea. Key pieces: NIP-94 media metadata, podcast:item tags, persistent audio player (mini-player bar), background playback, V4V streaming sats via NWC. Research Fountain.fm's Nostr event structure before implementing.