chore(dev): Group dev processes into phrocs categories

[charlesvien]

Problem

The phrocs sidebar shows all dev processes as one flat list, ordered by numeric name prefixes (1-code, 2-agent). The posthog repo groups its processes into categories, which reads much better as the process count grows.

Changes

Adds groups.layer to each process plus default_group and group_order, so the phrocs sidebar groups processes into Application, Packages and Tools. Drops the numeric name prefixes since grouping replaces them for ordering, which also makes code's depends_on entries match real process names. Stock mprocs (pnpm dev:mprocs) ignores the new keys, so the fallback keeps working.

How did you test this?

Ran both phrocs --config mprocs.yaml and mprocs --config mprocs.yaml headless: both parse the new config cleanly and fail only on the missing TTY.

Automatic notifications

• Publish to changelog?
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[greptile-apps]

_{Reviews (1): Last reviewed commit: "add phrocs layer groups to mprocs config" | Re-trigger Greptile}

[github-actions]

Pure dev-tooling config change — renaming process entries and adding grouping metadata to mprocs.yaml. No production impact whatsoever.