feat: automated stable releases, versioned ISOs, and Hub version badge

- Add release-stable.sh script with automatic tagging, CHANGELOG updates,
  GitHub/Gitea release creation, and VERSION file management
- Update iso/common.nix to include version from VERSION file in ISO filename
- Add VERSION file (current: 1.0.3)
- Polish OS version badge in Sovran Hub header (top-right)
- Update README.md download link to versioned ISO
- Update CHANGELOG.md with existing tags (v1.0.0 – v1.0.3)

Co-authored-by: arena-agent <297053741+arena-agent@users.noreply.github.com>

CHANGELOG.md

@@ -0,0 +1,59 @@
+# Changelog
+
+All notable changes to Sovran_SystemsOS will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+---
+
+## [1.0.3] - 2026-07-29
+
+### Added
+- Incremental stable updates
+
+## [1.0.2] - 2026-07-29
+
+### Added
+- Incremental stable updates
+
+## [1.0.1] - 2026-07-29
+
+### Added
+- Incremental stable updates
+
+## [1.0.0] - 2026-07-29
+
+### Added
+- Initial stable release of Sovran_SystemsOS
+- Full Bitcoin self-custody desktop environment
+- Integrated Sparrow Wallet, Bisq, and Bisq 2
+- Comprehensive Sovran Hub for service management
+- NixOS-based operating system with privacy and sovereignty focus
+- Support for Bitcoin Knots + BIP110, Electrs, LND, Ride The Lightning, BTCPay Server, and more
+- Server + Desktop hybrid mode with Matrix, Nextcloud, VaultWarden, and other self-hosted services
+- Automated installer with graphical GNOME desktop
+- Tor integration and onion services for all major components
+- Remote desktop (GNOME Remote Desktop) support
+- Role-based system configuration (desktop, server, server+desktop)
+- Detailed service credential management in the Sovran Hub
+
+### Changed
+- Moved from development/main branch to dedicated `stable` branch for production releases
+
+### Security
+- All services run with least-privilege principles where possible
+- Secrets stored in `/var/lib/secrets/`
+- Strong emphasis on user-controlled keys and self-sovereignty
+
+---
+
+## [Unreleased]
+
+### Added
+- (Nothing yet)
+
+[1.0.3]: https://git.sovransystems.com/Sovran_Systems/Sovran_SystemsOS/releases/tag/v1.0.3
+[1.0.2]: https://git.sovransystems.com/Sovran_Systems/Sovran_SystemsOS/releases/tag/v1.0.2
+[1.0.1]: https://git.sovransystems.com/Sovran_Systems/Sovran_SystemsOS/releases/tag/v1.0.1
+[1.0.0]: https://git.sovransystems.com/Sovran_Systems/Sovran_SystemsOS/releases/tag/v1.0.0