Excess memory usage during development

[absowoot]

Describe the bug Each time the compiler runs, 2 new processes are created for Elixir.Hologram.Compiler.CallGraph, and the old processes are not removed, leading to excess memory usage while developing.

To Reproduce Steps to reproduce the behavior:

1. Update extra_applications: [:logger, :runtime_tools, :observer, :wx]
2. Start server and run :observer.start()
3. Save any file and keep an eye on the Processes tab in observer (sort by memory)

Screenshots

Each spike is a file save

Environment information

• Hologram version: 0.6.5
• Elixir version: 1.18.4
• Erlang/OTP 28 [erts-16.1.2]
• Node.js version: 24.9.0
• Operating System: Mac Tahoe 26.1