Set up AUR publishing for tabex-bin and osyrra-bin

[anand-testcompare]

Summary

Wire shpitdev/pkgbuilds up to publish the existing package dirs to AUR:

• tabex-bin
• osyrra-bin

Scope

• create the corresponding AUR repos
• generate a dedicated SSH key for AUR publishing
• add the required repo secrets to shpitdev/pkgbuilds
• verify the existing publish workflow can push package updates

Required repo secrets

• AUR_USERNAME
• AUR_EMAIL
• AUR_SSH_PRIVATE_KEY

Verification

• confirm publish.yml runs with AUR secrets present
• run a manual workflow_dispatch or merge a package metadata change
• verify the expected AUR repos receive the updated PKGBUILD and .SRCINFO

Notes

Keep this scoped to shpitdev/pkgbuilds. Private GitHub release access is already handled separately; this issue is only about the final AUR publish path.