Enable isolated Remote speech and protect reading exports

Attach incoming software speech to reader sessions with lease checks, local output priority and isolated cancellation. Preserve every document fragment source for privacy checks and export reviewed browse current-line reading, spelling and phonetic output.

Verified focused reading and Remote race tests, complete review and external Remote race suites, private relay integration, speech regressions, affected-package vet, reader build and Tentacles make check. Audible speech, physical input/Braille and live interoperability remain unverified.

internal/app/speech_interrupt.go

@@ -49,6 +49,7 @@ func (worker *speechWorker) SetEnabled(enabled bool) {
 }
 
 func (worker *speechWorker) interruptLocked() {
+	worker.retire_remote_speech_locked()
 	if worker.hintCancel != nil {
 		worker.hintCancel()
 	}