fix(host): resolve Host-001 — exclude leader-only active-node check from /health/ready

code-reviews/Host/findings.md

@@ -8,7 +8,7 @@
 | Last reviewed | 2026-05-16 |
 | Reviewer | claude-agent |
 | Commit reviewed | `9c60592` |
-| Open findings | 11 |
+| Open findings | 10 |
 
 ## Summary
 
@@ -54,7 +54,7 @@ no safe workaround.
 |--|--|
 | Severity | High |
 | Category | Correctness & logic bugs |
-| Status | Open |
+| Status | Resolved |
 | Location | `src/ScadaLink.Host/Program.cs:135-145` |
 
 **Description**
@@ -81,7 +81,18 @@ checks and filter by tag). Add a regression test asserting a non-leader node ret
 
 **Resolution**
 
-_Unresolved._
+Resolved 2026-05-16 (commit `<pending>`). Root cause confirmed against
+`Program.cs`: the `/health/ready` mapping had no `Predicate`, so it executed all
+three registered checks including the leader-only `active-node` check, while
+`ActiveNodeHealthCheck` returns `Unhealthy` on any non-leader node — making a fully
+operational standby central node permanently report `503`. Fix: added
+`Predicate = check => check.Name != "active-node"` to the `/health/ready`
+`HealthCheckOptions`, so readiness now reflects cluster membership + DB connectivity
+only (REQ-HOST-4a); leadership remains reported solely by `/health/active`.
+Regression test `HealthCheckTests.HealthReady_Endpoint_ExcludesActiveNodeCheck`
+asserts the `active-node` check name does not appear in the `/health/ready`
+response body; it failed before the fix and passes after. Full Host suite green
+(156 passed).
 
 ### Host-002 — Akka.Persistence required by REQ-HOST-6 is not configured and not used