feat(db): Bun.SQL Kysely dialect for sqlite and postgres

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/db/src/ids.ts

@@ -0,0 +1,9 @@
+/** Time-sortable UUIDv7, generated in app code. */
+export function newId(): string {
+  return Bun.randomUUIDv7();
+}
+
+/** Current time as an ISO-8601 UTC string, the storage format for timestamps. */
+export function nowIso(): string {
+  return new Date().toISOString();
+}