Agentic UI: fix expired previews

[nightnei]

Related issues

• Fixes STU-1978

How AI was used in this PR

AI assisted

Proposed Changes

In the issue STU-1978 we needed to come up with an approach for expired previews. The solution in testing instructions.

Testing Instructions

1. Electron -> Feature Flags -> Enable Agentic UI
2. Create a new site
3. Click on:
   
4. Assert that everythign looks as before
   
5. Click on Share and wait till the preview is created
6. Assert that you see "Preview published" and teh next content for preview section
   
7. Open ~/.studio/cli.json
8. Set date for your snapshot as 1784209999143
9. Assert that you see "Preview updated 5 days ago"
   
10. Set date for your snapshot as 1784109999143
11. Assert that you see "Preview Expired", "The previous preview has expired." and button "Share a new one"
12. Click on "Share a new one"
13. Assert that it creates a preview

[wpmobilebot]

📊 Performance Test Results

Comparing ca51c16 vs trunk

app-size

Metric	trunk	ca51c16	Diff	Change
App Size (Mac)	1362.03 MB	1361.90 MB	0.13 MB	⚪ 0.0%

site-editor

Metric	trunk	ca51c16	Diff	Change
load	1026 ms	1066 ms	+40 ms	⚪ 0.0%

site-startup

Metric	trunk	ca51c16	Diff	Change
siteCreation	6507 ms	6519 ms	+12 ms	⚪ 0.0%
siteStartup	2393 ms	2395 ms	+2 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[sejas]

Works as expected. Thanks for fixing the expired preview sites. I tested it by modifying the snapshots date in cli.json

Before	After

[sejas]

We could consider unifying the isSnapshotExpired function under a module packages/common/lib to use it in the UI and CLI

studio/apps/cli/lib/snapshots.ts

Lines 14 to 18 in 4408fdf

	export function isSnapshotExpired( snapshot: Snapshot ) {
	const now = new Date();
	const endDate = addDays( snapshot.date, DEMO_SITE_EXPIRATION_DAYS );
	return endDate < now;
	}

[nightnei]

Great point, done