[Bug]: Dev seed snapshot has a migration history behind main, so vp run dev rejects it and reproductions start from empty state #24323

What happens

The dev seed that vp run dev loads for an isolated --home-dir (the read-only snapshot the dev runner copies in) has a migration history behind main. The server refuses it as incompatible, so every reproduction that needs realistic data either fails the seed or falls back to an empty fresh state, and the lead spends its budget creating synthetic threads instead.

Evidence

• 155 open friction entries from issue leads between 2026-10-21 and 2026-10-24: "Seed snapshot migration history incompatible", "Dev database snapshot had incompatible migration history; used fresh isolated state", "Real-data seed rejected newer migration history", "Automatic fixture migration rejected newer snapshot history", "Local data snapshot migration failed; fresh runtime then stalled on RPC".
• Leads work around it with migrate-dev-db --projects 1 --threads-per-project 2 or hand-built state; one capture spent its whole 35-minute budget on a splash screen loading 366 seeded threads before the fix above.

Expected

The snapshot the dev runner seeds from should always match main's migration history: regenerate it on main (a vp task, run in CI or on merge), or have the dev runner migrate the snapshot forward on load instead of rejecting it. A clear error that names the snapshot's and the binary's migration versions would also help.

Where

Freestyle VMs, repo at /home/ubuntu/t3code on main as of 2026-10-21 to 2026-10-24, vp run dev --home-dir <dir> with the default seed.