TASK22229: pilot shared relay forwarding utility

memory-bank/change-log.md

@@ -725,3 +725,42 @@ Validation:
 Follow-ups:
 
 - Optional future auth hygiene (separate guarded slice): replace verbose auth `console.log` diagnostics with structured logger usage once production logging requirements are confirmed.
+
+---
+
+### CL-019: TASK22229 P2-S1 relay forwarding pilot (proxy endpoint cluster)
+
+date: 2026-03-24
+author: Cline
+scope: `pages/api/middleware/relayForwarding.js`, `pages/api/endpoint/{getwatchedcasesproxy_api,getmyrepresentationsproxy_api,getrepresentationsproxy_api,getawaitingsubmissionproxy_api}.js`, `tests/phase21/endpoint-handler-contract.test.cjs`
+type: change
+rationale: Start Priority-2 by piloting a shared relay forwarding helper on a bounded proxy endpoint cluster to reduce duplicated token/hash/header/axios boilerplate while preserving endpoint contracts.
+impact: Maintainability and consistency improvement with no intended behavioral contract changes; error code/status/message and success payload contracts remain unchanged for migrated endpoints.
+status: completed
+
+Summary:
+
+- Added shared relay helper:
+    - `pages/api/middleware/relayForwarding.js`
+    - exports `relayGet({ queryUrl, res, errorResponse, transformData })`
+    - centralizes token fetch, relay URL + hash composition, `azureHeaders`, GET execution, success/error response handling, and logging
+- Migrated pilot endpoint cluster to `relayGet`:
+    - `getwatchedcasesproxy_api.js` (with existing payload transform preserved)
+    - `getmyrepresentationsproxy_api.js`
+    - `getrepresentationsproxy_api.js`
+    - `getawaitingsubmissionproxy_api.js` (with existing payload transform preserved)
+- Updated endpoint contract tests to mock `relayGet` for migrated routes while preserving existing assertions.
+
+Validation:
+
+- `node tests/phase21/api-contract-slice1.test.cjs` -> pass
+    - helper: 4/4
+    - file-handler: 53/53
+    - email-handler: 12/12
+    - endpoint-handler: 152/152
+    - documents-handler: 3/3
+
+Follow-ups:
+
+- P2-S2 rollout: migrate the next relay-heavy endpoint batch onto `relayGet`/shared forwarding utility pattern.
+- P2-S3 hardening: add shared timeout/retry config and redacted structured relay error logging policy.