DC-059: claim for Hermes

BACKLOG.md

@@ -382,3 +382,11 @@ Tickets DC-046 through DC-049 implement pluggable auth + email magic link. Sami
 7. **Never work on a task another bot has claimed** (status: in-progress).
 8. **Quality bar:** this is a public-release product. No hacks, no env-var workarounds, no per-machine patches. Fixes go in the shared codebase.
 9. **VERSION bump:** when a batch of tasks is done, bump patch version in package.json + VERSION file, update CHANGELOG, tag.
+
+### DC-059: Joi validation library — schema-based body validation middleware
+- **status:** in-progress
+- **owner:** hermes
+- **details:** Backend uses ad-hoc `if (!field) throw new ValidationError(...)` checks at every route entry point — 49 such checks across the codebase. They drift from the field semantics, allow unknown keys to flow through, and have no way to express structured types (CIDR, enum, port range). Tracked in `DC-PRODUCTION-GRADE-BACKLOG.md` as P1-1. Fix: `npm install joi@^18`, add `src/utilities/validate.js` exporting `validateBody(schema)` middleware factory + `schemas` object with reusable schemas. Apply to destructive routes: backups (schedule/restore/config), apps (deploy/restore/revert), assets (upload/logo). Add `__tests__/unit/validate.test.js` covering each schema's accept/reject/strip-unknown behaviour. Effort: ~2 hr.
+- **impact:** Closes P0-3 / P0-4 class of bugs at the schema layer instead of per-route. Prevents future routes from accepting arbitrary body fields. New routes copy-paste from `schemas.*` and get free validation.
+- **prerequisite:** None.
+