Align internal documentation and maintained examples

docs/internal/stage-transcribe.md

@@ -1,22 +1,36 @@
 # Stage: transcribe
 
 ## Purpose
+
 Generate raw per-speaker transcripts from prepared audio using WhisperX.
 
 ## Inputs
+
 - `audio/*.flac` from `prepare`
 
 ## Outputs
+
 - `transcripts/raw/<speaker>.json`
 
 ## Key Behavior
+
 - discovers prepared audio from manifest inputs or canonical audio directory.
 - derives speaker ID from `.flac` basename.
-- runs WhisperX with configured concurrency/retry settings.
+- dispatches WhisperX requests through a bounded worker pool.
 - validates each output as JSON.
 - writes run-local outputs then materializes canonical transcript outputs.
 
 ## Invariants
+
 - speaker basenames must be unique.
 - output path returned by adapter must match requested output path.
 - each successful output is validated before stage success.
+
+## Related Contracts And Tests
+
+- [WhisperX](../integrations/whisperx.md) owns HTTP, retry, timeout, and
+  cancellation semantics.
+- [Configuration](../config.md#pipeline) owns concurrency and other
+  operator-selected values.
+- Implementation and tests: `internal/stage/transcribe.go`,
+  `internal/stage/transcribe_test.go`