Protect initial pipeline stage resume semantics

docs/internal/stage-transcribe.md

@@ -31,6 +31,19 @@ Generate raw per-speaker transcripts from prepared audio using WhisperX.
 - each successful output is validated before stage success, and cancellation or
   incomplete dispatch cannot be reported as a successful result.
 
+## Resume Evidence
+
+Transcribe records a versioned semantic-configuration fingerprint containing
+the Narratio-visible WhisperX service URL and recognition language. Changes to
+either rerun transcription and stale its fixed descendants while leaving
+prepare reusable. Retry count/delay, concurrency, timeout, credentials, and
+diagnostic locations are operational and do not change this evidence.
+
+WhisperX models or private service configuration not exposed by Narratio's
+adapter contract cannot be fingerprinted; use `--force` after changing them.
+An existing successful transcribe record without evidence reruns once when
+selected.
+
 ## Related Contracts And Tests
 
 - [WhisperX](../integrations/whisperx.md) owns HTTP, retry, timeout, and
@@ -38,4 +51,6 @@ Generate raw per-speaker transcripts from prepared audio using WhisperX.
 - [Configuration](../config.md#pipeline) owns concurrency and other
   operator-selected values.
 - Implementation and tests: `internal/stage/transcribe.go`,
-  `internal/stage/transcribe_test.go`
+  `internal/stage/transcribe_test.go`,
+  `internal/stage/semantic_contracts_initial.go`, and
+  `internal/stage/semantic_contracts_initial_test.go`