Await session state before computing the customization migration hint - #334958

PR classified as team-member.

✅ Head commit a3e8f07 is signed by aeschli with trusted key 704514F880A596860D2200B8E513BD990A2907F7 — approval requirement reduced from 2 to 1.

✅ Collaborator approvals: 1/1 (lszomoru).

✅ No newly added runnable binary files.

✅ No protected engineering system files changed.