Protect initial pipeline stage resume semantics

docs/internal/stage-merge.md

@@ -29,9 +29,23 @@ Normalize raw transcript inputs and merge into base transcript via Seriatim.
 - base transcript must validate before stage success.
 - report output is config-gated.
 
+## Resume Evidence
+
+Merge records a versioned semantic-configuration fingerprint for the Seriatim
+merge operation, output schema, coalesce gap, and every configured advanced
+merge transformation. A change reruns merge and stales only its fixed
+descendants; prepare and transcribe remain reusable. Binary path, timeout,
+report emission, logs, and diagnostic retention are operational exclusions.
+
+Configuration or resources loaded privately inside Seriatim are outside
+Narratio's observable contract and require `--force` when changed. An existing
+successful merge record without evidence reruns once when selected.
+
 ## Related Contracts And Tests
 
 - [Seriatim](../integrations/seriatim.md) owns subprocess and output semantics.
 - [Configuration](../config.md#pipeline) owns operator-selected Seriatim values.
 - Implementation and tests: `internal/stage/merge.go`,
-  `internal/stage/merge_test.go`
+  `internal/stage/merge_test.go`,
+  `internal/stage/semantic_contracts_initial.go`, and
+  `internal/stage/semantic_contracts_initial_test.go`

docs/internal/stage-prepare.md

@@ -57,6 +57,21 @@ mapping, while the isolated legacy reader rejects ambiguous fallback matches.
 - managed `previous/` state represents only the current requirement set.
 - `manifest.inputs` ordering is deterministic (`kind`, `path`).
 
+## Resume Evidence
+
+Prepare records a versioned semantic-configuration fingerprint for the
+resolved campaign/session selection, local-versus-S3 audio mode and canonical
+audio names, stable-input ownership/presence, previous-session identity, and
+the effective previous-artifact requirement set. A change reruns prepare and
+stales its fixed descendants. Existing successful records without this
+evidence rerun once when selected.
+
+Workspace, spool, and cache placement and absolute source relocation are not
+semantic when logical selection, canonical names, and bytes are equivalent.
+The fingerprint deliberately does not read or rehash large audio. Prepared
+input checksums remain the content provenance; force prepare after changing
+source bytes that are not otherwise reflected by the semantic selection.
+
 ## Related Contracts And Tests
 
 - [Configuration](../config.md) owns audio selection, stable input fields, and
@@ -66,5 +81,8 @@ mapping, while the isolated legacy reader rejects ambiguous fallback matches.
 - [Storage Internals](storage.md) and [Artifact Internals](artifacts.md) explain
   the internal collaborators.
 - Implementation and tests: `internal/stage/prepare.go`,
-  `internal/stage/prepare_test.go`, `internal/audio/s3_audio_test.go`,
+  `internal/stage/prepare_test.go`,
+  `internal/stage/semantic_contracts_initial.go`,
+  `internal/stage/semantic_contracts_initial_test.go`,
+  `internal/audio/s3_audio_test.go`,
   `internal/previouscache/*_test.go`

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`

docs/operations.md

@@ -88,7 +88,9 @@ Canonical stage order:
 
 Execution rules:
 
-- succeeded stages are skipped unless `--force` is set;
+- succeeded stages are skipped unless `--force` is set; stages with semantic
+  configuration contracts additionally require matching versioned evidence,
+  and missing legacy evidence causes a safe one-time rerun;
 - `run` continues interrupted or partially completed sessions by running non-succeeded stages;
 - forcing a stage marks succeeded transitive dependents as `stale` before the
   replacement runs; render and extract are independent siblings; and
@@ -97,6 +99,15 @@ Execution rules:
   repeated self-skip with the same reason and no outputs is stable and does not
   perpetually rerun dependent work.
 
+Prepare, transcribe, and merge currently provide semantic-configuration
+evidence. Changing prepare selection semantics reruns all fixed descendants;
+changing WhisperX language/service identity reuses prepare; and changing a
+Seriatim merge transformation reuses prepare and transcribe. Operational
+timeouts, retry/concurrency tuning, executable paths, workspace/cache/spool
+placement, reports, diagnostics, and secret values are excluded. Configuration,
+models, prompts, modules, or resources loaded privately inside external tools
+remain unobservable to Narratio and require an explicit `--force` after change.
+
 An explicit self-skip is a durable `skipped` stage outcome that later runs
 reconsider. It differs from successful no-output execution: disabled `render`
 and `publish`, and absent or no-executable `analyze`, record `succeeded` with

docs/roadmap/implementation.md

@@ -303,7 +303,7 @@ configuration before selectable profiles can change those values.
 
 ## Stage 4 — Prepare, Transcribe, And Merge Semantic Contracts
 
-**Status: Pending**
+**Status: Completed**
 
 ### Goal