docs(workstation-v0): add Mac-on-Linux operator runbook sections

[Copilot]

Operators had no concise reference for the full install sequence, reboot expectations, Mac polish/keyboard/Lampstand validation, or how to distinguish hard failures from soft gaps.

Changes to docs/workstation/RUNBOOK.md

• Install sequence — numbered all 15 steps with their install.sh function names so operators know exactly what runs and in what order
• rpm-ostree reboot notes — explicit 3-step sequence: layer → rpm-ostree status → reboot → re-run; notes steps 2–15 are idempotent
• Warnings vs hard failures table — ok/warn/error/info levels mapped to blocking/non-blocking with copy-pasteable triage commands using --json output
• Mac polish helper (§5) — check-mac-polish.sh expected key=value output, mac-screenshot.sh subcommands, Sushi Quick Look note
• Keyboard policy helper (§6) — check-keyboard-policy.sh expected output, policy_ok=yes acceptance signal, SOURCEOS_REMAP_BACKEND override example
• Lampstand checks (§7) — check-lampstand-unit.sh, doctor JSON filter for lampstand results, all sourceos search and unit lifecycle commands
• Known gaps & non-goals (§10) — documents soft gaps (Lampstand, fusuma, GNOME extensions, PATH timing) and explicit non-goals (production readiness, non-GNOME/non-Fedora hosts, no script modifications)

No implementation scripts were modified.

[mdheller]

Replay review:

This runbook content is useful but the PR is non-mergeable against current main; do not merge stale history.

Preserve the useful content:

• exact install sequence and function names;
• rpm-ostree reboot guidance;
• warning vs hard-failure semantics;
• Mac polish, keyboard policy, and Lampstand triage commands;
• explicit known gaps and non-goals.

Recommended action: replay these sections into the current workstation runbook as part of the fresh workstation acceptance cleanup branch. After the replacement PR is open, close this PR as superseded.