seam sweep: move the TieredBackend witness into production code (no version bump)

A witness in a _test.go file fires on go test and go vet but NOT on go build alone — and a build-only step is exactly how the R-88 Part 2 near-miss would have shipped. Moved beside the type it pins, and added one for AgentVersionReporter. No defect found: quiesceBackend and *Client both satisfy their interfaces today. No version bump, no deploy — compile-time only.
2026-07-27 18:23:50 +02:00
parent ca013c8d27
commit 8f46495426
3 changed files with 28 additions and 19 deletions
@@ -230,3 +230,9 @@ func classifySupportErr(err error) SupportState {
 	}
 	return SupportUnknown
 }
+
+// AgentVersionReporter witness. Asserted at SupportsWithSource (`p.(AgentVersionReporter)`); a failed
+// assertion falls back from the version gate to the live probe. That degrade is benign — both paths
+// decide correctly — but *Client is the production prober and losing the version path would silently
+// turn every MinAgent floor into a probe round-trip, which is a behaviour change nobody would see.
+var _ AgentVersionReporter = (*Client)(nil)