fix(alerts): show the interval alert will check

[anirudhpillai]

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Problem

Users find it confusing that setting alert to run 'hourly' doesn't check the last hour on the trend insight

Changes

Explicitly show the interval alert will check.

Did you write or update any docs for this change?

• [ ] I've added or updated the docs
• [ ] I've reached out for help from the docs team
• [ ] No docs needed for this change

How did you test this code?

Tested locally

[posthog-bot]

📸 UI snapshots have been updated

3 snapshot changes in total. 0 added, 3 modified, 0 deleted:

• chromium: 0 added, 3 modified, 0 deleted (diff for shard 1, diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

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[github-actions[bot]]

Size Change: 0 B

Total Size: 2.57 MB

ℹ️ View Unchanged

Filename	Size
frontend/dist/toolbar.js	2.57 MB

_{compressed-size-action}

[posthog-bot]

📸 UI snapshots have been updated

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• chromium: 0 added, 2 modified, 0 deleted (diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

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[posthog-bot]

📸 UI snapshots have been updated

1 snapshot changes in total. 0 added, 1 modified, 0 deleted:

• chromium: 0 added, 1 modified, 0 deleted (diff for shard 7)
• webkit: 0 added, 0 modified, 0 deleted

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📸 UI snapshots have been updated

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[!CAUTION]

Detected flapping snapshots

These snapshots have auto-updated more than once since the last human commit:

• scenes-app-surveys--survey-templates--dark.png (chromium, shard 7)

The flippy-flappies are deadly and must be fixed ASAP. They're productivity killers. Run pnpm storybook locally and make the fix now. (Often, the cause is ResizeObserver being used instead of the better CSS container queries.)

• chromium: 0 added, 1 modified, 0 deleted (diff for shard 7)
• webkit: 0 added, 0 modified, 0 deleted

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