chore: stop exposing development branches on Packagist

[ibourgeois]

Context

As a maintainer publishing Beacon to Packagist, I need Packagist to stop surfacing development branches as installable package versions so users see only the intended release channels.

Acceptance Criteria

• identify why Packagist is indexing Beacon development branches as visible package versions
• update the repository or Packagist configuration so non-release branches are no longer exposed as normal install targets
• preserve tagged release publication behavior for stable versions
• document any maintainer steps required to keep Packagist branch exposure under control
• verify the resulting Packagist package view matches the intended release strategy

Notes

This should align Packagist behavior with Beacon's release process and reduce confusion for users browsing available versions.