fix(orchestrator): run the tree timer a minute after each run

Root cause: a pkgmgr branch tree run takes 72.6 s real (55.5 s user) on
this host, while TimeoutStartSec=55 killed every run; the timer fired
again each minute, so the service burned a core and branch-tree.json
never appeared.

- kvb-orchestrator-tree.timer: OnActiveSec=30s plus
  OnUnitInactiveSec=60s instead of OnCalendar=minutely, so runs never
  overlap and the next one starts 60 s after the last ended.
- kvb-orchestrator-tree.service: TimeoutStartSec=600 and CPUQuota=50%.
- orchestrator.sh restarts the timer on install so the new schedule
  takes effect; README and requirement 001 follow.

🎯 Fix: 92 %
💥 Break: 4 %
💸 Cost: 100 %
⏱️ Time: –
🛡️ Security: 100 %
🏆 Score: 88
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

orchestrator/systemd/kvb-orchestrator-tree.timer

@@ -1,8 +1,9 @@
 [Unit]
-Description=Agent Orchestrator tree every 60 s
+Description=Agent Orchestrator tree a minute after its last run
 
 [Timer]
-OnCalendar=minutely
+OnActiveSec=30s
+OnUnitInactiveSec=60s
 AccuracySec=1s
 
 [Install]