feat: integrate platform backend and application interfaces

server/migrations/0001_v1_baseline.sql

@@ -0,0 +1,8 @@
+-- V1 baseline. The in-memory adapter is used for local bootstrap; production
+-- migrations must keep these ownership, snapshot, and ledger boundaries.
+CREATE TABLE IF NOT EXISTS schema_migrations (
+  version TEXT PRIMARY KEY,
+  applied_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+INSERT INTO schema_migrations(version) VALUES ('0001_v1_baseline') ON CONFLICT DO NOTHING;