fix(app): 503 on storage failures, validated currency, lock release on shutdown, per-IP login limit, unit-only npm test

refactor(domain): move MAX_CENTS to money, deterministic shuffle in tests

fix(domain): guard split allocation and balance invariants

feat(domain): compute net balances and simplified debts

feat(domain): add largest-remainder split allocation

fix(domain): harden schemas, ULID monotonicity and amount parsing

feat(domain): add monotonic ULID generator and money parsing/formatting

feat(domain): add core types and zod schemas

chore: scaffold SvelteKit project with Tailwind, Vitest, adapter-node