fix: harden auth and investment synchronization

Resolve A01-A10 and C01-C07 from the backend audit.
Preserve auth failures, forced candle reconciliation and forecast freshness.
Validate MOEX responses and nested HTTP errors; remove unused legacy paths.

Verified: 209 unit tests, 262 SQLite e2e tests on Linux, OpenAPI and durability.
Record the remaining macOS native SQLite abort in the audit.

test/tbank-catalog-discovery.e2e-spec.ts

@@ -22,7 +22,7 @@ describe('shared catalog discovery (SQLite)', () => {
     }) as never,
   );
   const upstream = { findShares: jest.fn(), findBonds: jest.fn() };
-  const access = new TbankAccessService(prisma, tokens, upstream as never);
+  const access = new TbankAccessService(prisma, tokens);
   const repository = new CatalogDiscoveryRepository(prisma);
   const createService = () =>
     new CatalogDiscoveryService(