v1.0.1 — fix /fresh not appearing in command list

Fix

/fresh never appeared in the command list due to two scope issues:

1. compaction engine scope — it's a per-agent preset-mount service, not a global ctx.compaction a profile-bundle plugin can reach. Now uses ctx.agentPresets.serviceFor(agent, 'compaction') (same as auto-compact).
2. command registration — was registered inside a ctx.inject(['compaction']) fiber that never activated (isolate scope), so the command never entered the global layer. Now registered in root ctx via ctx.effect + ctx.commands.register.

Verified

• [fresh-start] installed: /fresh command registered
• 19 tests ALL PASS