fix(desktop): allow preview automation in agent-created threads

[t3dotgg]

Preview automation fails from agent-created threads because their desktop runtime tab IDs can exceed the public 128-character tab ID limit. Desktop IPC rejects the status result after the browser action has already run.

Use a desktop-only status schema for this IPC result. This keeps the public contract limit intact while allowing the internal runtime ID to return through IPC. The manager and bridge types now describe the same boundary.

Tests:

• vp test run apps/desktop/src/ipc/methods/preview.test.ts
• vp run --filter @t3tools/contracts typecheck
• vp run --filter @t3tools/web typecheck
• targeted desktop typecheck for the changed files

Fixes #7720

Made with GPT-5.6 Sol using Codex.

---

Note

Low Risk
Contract boundary change limited to desktop IPC and bridge types; public automation status validation stays the same.

Overview
Fixes preview automation failing on agent-created threads when the desktop runtime tab ID exceeds the public 128-character PreviewTabId limit. Automation could run in the browser, but the desktop automation status IPC path then rejected the encoded result because it used the public PreviewAutomationStatus schema.

Introduces DesktopPreviewAutomationStatusSchema, which keeps the public status fields but types tabId with DesktopPreviewTabIdSchema (trimmed, non-empty, no 128-char cap). The preview IPC handler, preview manager, and DesktopPreviewBridge.automation.status now use that desktop-only result type so internal runtime IDs can round-trip over IPC.

The public PreviewAutomationStatus contract and its 128-character tab ID limit are unchanged for cross-boundary APIs.

^{Reviewed by Cursor Bugbot for commit 90d266a. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Fix preview.automationStatus IPC to allow null tabId

Introduces DesktopPreviewAutomationStatusSchema in ipc.ts that extends PreviewAutomationStatus but permits tabId to be null instead of requiring a valid tab identifier. The preview.automationStatus IPC handler and PreviewManager.automationStatus return type are switched to the new schema. Risk: out-of-tree consumers expecting a non-null tabId from the automationStatus IPC method will now encounter null values for agent-created threads.

^{Macroscope summarized 90d266a.}

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.3 KiB	13.3 KiB	−21 B (−0.2%)	15.1 KiB	✅
Codex	Thread snapshot wire	6.9 KiB	6.9 KiB	+1 B (+0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.4 KiB	6.4 KiB	−22 B (−0.3%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	55.6 KiB	55.6 KiB	−44 B (−0.1%)	66.4 KiB	✅
Codex	Live turn messages	11	10	−1 (−9.1%)	21	✅
Claude	Total thread wire	13.3 KiB	13.5 KiB	+153 B (+1.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	6.9 KiB	6.9 KiB	0 B (0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.4 KiB	6.6 KiB	+153 B (+2.3%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	56.4 KiB	57.9 KiB	+1.4 KiB (+2.5%)	66.4 KiB	✅
Claude	Live turn messages	11	11	0 (0.0%)	21	✅

Baseline: 850e458 · PR result: 90d266a · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 109.4 KiB
• Claude decoded thread snapshot: 110.1 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Approved at 90d266a

Macroscope's review found this PR approvable — This is a narrowly scoped desktop IPC contract fix that allows existing preview automation to round-trip long internal runtime tab IDs without changing the public 128-character contract. The manager logic and downstream behavior remain unchanged, with regression coverage for both boundaries.

^{You can add or adjust custom eligibility rules. Learn more.}