Fix P0 issues in financial ingestion architecture

- Wrap snapshot updates in transactions with error context for each child table
- Add sidecar retry with exponential backoff (3 attempts, 2s base, 10s max, 30% jitter)
- Add HTTP timeout (30s per request) and SEC rate limiting (10 req/s) in Rust
- Add XBRL validation with status reporting (checks root element, tag balance)

lib/server/utils/index.ts

@@ -0,0 +1,22 @@
+export {
+  normalizeTicker,
+  normalizeTickerOrNull,
+  normalizeTags,
+  normalizeTagsOrNull,
+  normalizeOptionalString,
+  normalizeRecord,
+  normalizePositiveInteger,
+  nowIso,
+  todayIso
+} from './normalize';
+
+export {
+  asRecord,
+  asOptionalRecord,
+  asPositiveNumber,
+  asBoolean,
+  asStringArray,
+  asEnum
+} from './validation';
+
+export { withRetry, type RetryOptions } from './retry';