Add FAM_OS package

[demimagic-ML]

Summary

Add the x86_64 FAM_OS package for Omarchy 4 with:

• a release-archive-pinned PKGBUILD
• normal pacman install, upgrade, and removal messages
• Omarchy package updater metadata for stable, rc, and edge channels
• automatic checksum refresh from the signed FAM_OS release manifest
• no root-time writes into a desktop user home

Project site: fam-os.demimagic.chatgpt.site

Why FAM

FAM_OS is a Linux-native engineering agent built around durable, resumable goals: it works in isolated candidate workspaces, invokes local models or Codex, executes OS and application tools, and applies changes only after file, command, browser-level, or application-level verification. Packaging it for Omarchy provides a reproducible system installation for the service, launchers, application-testing dependencies, user units, native widget integration, and lifecycle hooks while preserving user-owned configuration and goal state across upgrades and removals.

The recipe consumes the signed FAM_OS v0.1.1 release and pins its deterministic source archive to SHA-256 81f1af76184604157be4354b19762d26afc894c32b7d449b87d0f74424218b2c. FAM installation and Omarchy user setup remain separate lifecycle steps; package installation does not silently enable plugins or mutate user configuration.

Verification

The v0.1.1 release workflow completed:

• the complete 87-test Omarchy contract, integration, and unit suite
• the real browser project build and behavior lifecycle
• deterministic source archive and checksum generation
• x86_64 Arch package build, installation, and runtime verification
• signed source/package artifacts and signed SHA256SUMS using the pinned FAM release key
• GitHub build provenance attestations

The submitted Omarchy recipe was also selected correctly by bin/repo build --dry-run --package fam-os. A local full upstream-builder attempt stopped in the builder image's existing keys.openpgp.org bootstrap before the FAM recipe was executed; the release workflow's Arch build and install passed. aarch64 remains experimental and is intentionally not part of this Omarchy package recipe.