Protect transcript refinement resume semantics

docs/internal/stage-trim.md

@@ -33,6 +33,19 @@ When `trim.enabled=false`:
 - bounds output exists only in enabled trim path.
 - render-debug output is diagnostic and not a declared stage output.
 
+## Resume Semantics
+
+The versioned semantic fingerprint covers enablement, the bounds prompt and
+profile identifiers, the Scriptorium configuration identity, transcript input
+name, sticky session variable, bounds and trimmed output identities, and the
+Seriatim trim operation. Diagnostic bounds rendering, diagnostic output paths,
+timeouts, executable paths, and optional reports are operational and do not
+invalidate the canonical trimmed transcript.
+
+Narratio cannot inspect prompt, profile, or configuration content that
+Scriptorium or Seriatim privately resolves behind a stable identifier. Force
+`trim` after changing such private content without changing its identifier.
+
 ## Related Contracts And Tests
 
 - [Scriptorium](../integrations/scriptorium.md) owns bounds generation and
@@ -40,4 +53,5 @@ When `trim.enabled=false`:
 - [Seriatim](../integrations/seriatim.md) owns transcript trimming behavior.
 - [Configuration](../config.md#pipeline) owns trim fields and defaults.
 - Implementation and tests: `internal/stage/trim.go`,
-  `internal/stage/trim_test.go`
+  `internal/stage/trim_test.go`,
+  `internal/stage/semantic_contracts_refinement.go`