Add Seriatim configuration contract

examples/pipeline.minimal.yml

@@ -13,7 +13,16 @@ whisperx:
   concurrency: 2
 
 seriatim:
-  timeout: 30s
+  binary: "seriatim"
+  timeout: "10m"
+  output_schema: "seriatim-intermediate"
+  coalesce_gap: 3.0
+  report: true
+  env:
+    overlap_word_run_gap: 1.0
+    overlap_word_run_reorder_window: 1.0
+    backchannel_max_duration: 2.0
+    filler_max_duration: 1.25
 
 audita:
   timeout: 1h