Conversation ProjectsHelper#sanitize_repo_path

This helper is meant to prevent leaking full disk paths to repositories in user-facing error messages; it blacklists the known repository storage paths. It will stop working in the Gitaly world, because the process that runs this helper (Unicorn or Sidekiq) does not know what to put on its blacklist.

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Stages:

• RPC Design: Create Issue

• ~"Client Implementation": Create Issue

• Server Implementation: Create Issue

• ~"Acceptance Testing": Create Issue

RPC Endpoints:

• Endpoint::Name

Known Client Routes:

• Known client endpoints

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