[P3] Dev DX: native sqlite driver ABI mismatch on newer Node; PORT→OS_PORT; auth Origin requirement #1875

Problem (dev DX)

1. The dev server defaults to the native better-sqlite3 driver; its prebuilt binary's ABI doesn't match newer Node (e.g. Node 25 → NODE_MODULE_VERSION mismatch), so objectstack dev fails to persist until you manually rebuild from source. Consider defaulting dev to the wasm driver, or shipping prebuilds for current Node.
2. Minor: PORT env var is deprecated in favor of OS_PORT (warns on every boot). better-auth email sign-in returns 403 without an Origin header (trips simple API clients).

Affected

driver packaging / CLI dev defaults / auth + env DX.

Found while runtime-testing objectstack-ai/templates (all 9 templates via objectstack dev all) on @objectstack 9.5.1. Build + typecheck pass; these only surface at runtime.