fix: recover Server.name from storage on alarm wake

[jcheese1]

Summary

• Persist Server.name to DO storage in setName(), recover it at the top of alarm() when #_name is unset
• Fixes crash when this.name is read inside onAlarm() or schedule callbacks after a cold wake (alarm is the only entry point that never called setName())
• Real-world impact: Agent.runWorkflow() reads this.name to inject __agentName — crashes when triggered by this.schedule()

Test plan

• New AlarmNameServer test DO with seed endpoint that writes name to storage without calling setName(), simulating cold wake
• Test asserts nameWasCold: true (proving storage recovery path was exercised, not a warm instance no-op)
• Test asserts this.name returns correct value inside onAlarm()
• All 33 existing tests pass

[changeset-bot]

⚠️ No Changeset found

Latest commit: 56e4099

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR