fix(api): quote camelCase identifiers + ParseIntPipe on route :id (Postgres)

[Danswar]

Problem

A class of HTTP 500s on prod traces to the MySQL→Postgres migration. Postgres folds unquoted identifiers to lowercase and is stricter on function signatures, so raw-SQL fragments that worked on MySQL now error at runtime. Mapped from 7 days of prod Postgres logs:

• invalid input syntax for type integer: "NaN" (94) — top volume
• missing FROM-clause entry for table "userdata" (66)
• column ... does not exist on camelCase columns (issueId, userDataId, linkId, organizationName)
• function round(double precision, integer) does not exist

Changes

ParseIntPipe on route :id handlers (buy/sell/swap controllers — get/update/history):
A non-numeric :id made +id → NaN, bound as an integer query param → 500. Now rejects with a proper 400.

Quote camelCase aliases/columns in raw query fragments:

• support-issue.service.ts — "userData", "organizationName", "issueId" (list search + message-stats subqueries)
• deposit-route.service.ts — "userData"."paymentLinksConfig" (payment-link key lookup)
• bank-data.service.ts — "userDataId" (metadata-less .update('bank_data') QB)
• payment-link-payment.service.ts — "linkId"/"maxId" (most-recent-payments subquery join)

Casing verified against the InitialSchema migration (source of truth for the actual column names).

ref-reward.service.ts — cast ROUND(SUM(...)::numeric, 0); Postgres has no round(double precision, integer) overload.

Scope

Limited to the confirmed serving-path 500s. Deliberately excludes the gs.service relation "sell" STI issue and the /gs/debug ad-hoc admin-SQL errors (admin-console only, not application queries).

Validation

• ESLint clean; affected controller specs pass (ts-jest type-checks the string→number param change at call sites).
• Build clean for the changed files. The only build errors are pre-existing baseline (eventsource / @opentelemetry/* deps not present locally; resolved by a fresh install in CI).