Task: Remediate X-01 preview data injection target

Identity

Task ID: 20260827-x01-preview-injection-9c4e2a71
Mode: Feature
Branch: codex/20260827-x01-preview-injection-9c4e2a71-x01-preview-injection-9c4e2a71
Worktree: D:\Datas\OthersProjects\makelore-x01-preview-injection-9c4e2a71
Base commit: 2f346687b1
Owner: codex
Status: Ready for Integration

X-01 live-acceptance remediation on exact client coordinator HEAD 2f346687b173137135dbd5259511d23505ff08dd.
Fix the confirmed root injectProjectData preview failure in electron/agent-browser/module.ts by passing the intended preview target Origin explicitly into root preview-data installation.
Add the narrow Agent Browser regression test and this task-scoped record only.

Follow Data Service P0 spec §10.4 and §14 groups 2 and 13, plus the X-01 remediation finding. Preserve explicit opt-in, exact-Origin capability binding, child/sessionRef behavior, lifecycle cleanup, and ordinary browser navigation without data injection.
The confirmed cause is that open() initializes record.url to the target, prime navigation to about:blank mutates it, and root installation later derives Origin from the mutated URL. The fix must carry the target URL directly; it must not weaken Origin checks or add a second browser/preload.
Only this task worktree may be modified. The occupied coordinator worktree, its untracked X-01 probe scripts, all other source files, and the prior ML-09 source worktree are read-only context.
Do not alter child/sessionRef installation semantics, route behavior, server code, unrelated E2E selectors, or canonical project memory.

Result: Passed on 2026-08-27.
Concurrent gate ran check_project_docs.py, then task_context.py start against the occupied coordinator worktree with --base-ref 2f346687b173137135dbd5259511d23505ff08dd; status JSON verified this task ID, feature mode, absolute worktree/branch, and exact base.
Read the required MakeLore project-memory startup set, the coordinator task record, Agent Browser architecture/data-flow seams, and the X-01 scope. The coordinator owns the parent worktree and its live probes; this task owns only the isolated module/test/record paths, with no unresolved semantic conflict.

Passed the intended targetUrl explicitly to the root preview-data installation call. Root session Origin now derives from that stable target URL even when the prime about:blank navigation updates record.url; child/sessionRef installation remains on its existing call path.
Added a narrow Agent Browser regression whose fake prime navigation emits did-navigate for about:blank. Before the fix it observed origin: "null"; after the fix it observes http://127.0.0.1:4173.

Inspect the current root/child preview installation seam and add a failing regression proving a prime about:blank navigation cannot change the Origin used for root injection.
Pass the intended target URL through root installation with the smallest signature/call-site change; keep child/sessionRef handling unchanged.
Run focused Agent Browser/preview tests, typecheck, scoped lint and diff/doc gates, then commit once with a clean isolated worktree.

Red-first regression: pnpm exec vitest run tests/unit/agent-browser-core.test.ts -t "uses the target Origin when the prime navigation reports about:blank" --maxWorkers=1 failed as expected before the implementation (received origin: "null").
Focused tests: pnpm exec vitest run tests/unit/agent-browser-core.test.ts tests/unit/preview-data-session.test.ts --maxWorkers=1 — 2 files, 84 tests passed.
pnpm run typecheck — passed.
pnpm exec eslint electron/agent-browser/module.ts tests/unit/agent-browser-core.test.ts — passed.
git diff --check — passed.
No Electron E2E or live X-01 acceptance was run in this narrow remediation; the coordinator must rerun live acceptance after integration.

Parent coordinator should integrate the single commit and rerun X-01 with the real PostgreSQL and signed-in MakeLore preview. Do not treat this repository-local focused verification as live acceptance.