feat: schema version tracking, SHA256 integrity, setup scripts, bug fixes

release/migrate_add_schema_version.sql

@@ -0,0 +1,11 @@
+-- Migration: Add schema version tracking table
+-- Date: 2026-05-15
+-- Usage: psql -U accusys -d momentry -f migrate_add_schema_version.sql
+
+CREATE TABLE IF NOT EXISTS schema_migrations (
+    id SERIAL PRIMARY KEY,
+    filename TEXT NOT NULL UNIQUE,
+    checksum TEXT NOT NULL,
+    applied_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    duration_ms INTEGER DEFAULT 0
+);