Build RPM packages on release

[javuto]

Implementation of #1028

Summary

• Added RPM package generation alongside existing DEB packages.
• Included API and TLS sample configurations in both package formats.
• Added systemd units for osctrl-api and osctrl-tls, generated from deploy/config/systemd.service.
• Added package lifecycle scripts to create the osctrl account, reload systemd, and safely disable services during removal.
• Preserved existing configurations during upgrades with config|noreplace.
• Removed obsolete CLI service hooks that could delete the shared osctrl account.

Validation

• GoReleaser configuration validation passed.
• Package script syntax checks passed.
• Generated systemd units contain no unresolved placeholders.
• git diff --check passed.
• Full package builds were not run because the Go toolchain is blocked in the sandbox.