87871eaefb
Injector.java:391 caught only RuntimeException around the herdr send seam. PR #543 (fleetd #538) widened StatusPoller's per-target catch to Throwable so the polling loop now survives an Error there, which means it comes back round — and Injector's narrower catch let the poisoned message stay QUEUED (the loop peeks, not polls), so the next round re-sent the same text into the member's pane. Widen the catch to Throwable, matching #543 one layer down. sendError's declared type widens from RuntimeException to Throwable to keep compiling; its only consumer (CompletableFuture.completeExceptionally(Throwable)) already accepts that type, so no other caller-visible behavior changes. The ordinary HerdrException/RuntimeException path is unchanged. Adds three tests: an Error at the send seam is dropped and marked NOT_DELIVERED, a second onStatus round does not re-send it, and a HerdrException control proves the ordinary path is untouched.