Add validator chain config overrides

docs/cli.md

@@ -45,8 +45,9 @@ Flags:
   Defaults to `./notarius-output`.
 - `--diagnostics-dir path`: diagnostics work directory override for this
   invocation.
-- `--llm-profile id`: override every effective LLM-capable module binding to
-  use one Scriptorium profile ID.
+- `--llm-profile id`: override every effective LLM-capable pipeline module
+  binding to use one Scriptorium profile ID. Validator-specific profiles are
+  not overridden.
 - `--session-id id`: pass a stable prompt session identifier through LLM-backed
   module calls.
 - `--reference selector=path`: bind a reference path to a chunk, extractor,

docs/config.md

@@ -131,8 +131,9 @@ Artifact lane fields:
 - `extract`: required module binding.
 - `merge`: optional module binding. Default module is `appendorder`.
 - `normalize`: optional module binding. Default module is `noop`.
-- `validators`: reserved for future configurable validator chains. Non-empty
-  lists are rejected by current configuration validation.
+- `validators`: deprecated lane-level validator list. Non-empty lists are
+  rejected; use `extract.validators`, `merge.validators`, or
+  `normalize.validators`.
 - `references`: optional compatibility alias for extractor reference bindings.
   Lane bindings override pipeline-level bindings for the same slot.
 
@@ -234,12 +235,28 @@ Binding fields:
 - `options`: optional module-specific settings.
 - `references`: optional reference bindings. Supported only for `chunk`,
   `extract`, `merge`, and `normalize` bindings. `input` and `output` bindings
-  reject this field during validation. Validator bindings are reserved for a
-  future validator-chain feature and are rejected when configured.
+  reject this field during validation.
+- `validators`: optional stage-local validator chain override. Supported only
+  for `chunk`, `extract`, `merge`, and `normalize` bindings. Omit the field to
+  use the production default chain; set `validators: []` to force an empty
+  chain; set a non-empty list to use exactly those validators in configured
+  order.
+
+Validator bindings use the same shorthand or object module-binding form, but
+only these fields are supported:
+
+- `module`: validator key.
+- `llm_profile`: optional Scriptorium profile ID for LLM-backed validators.
+- `options`: optional validator-specific settings.
+
+Validator bindings reject `references`, `retries`, and nested `validators`.
+During resolution, deterministic validators reject explicit `llm_profile`
+values.
 
 The `--llm-profile` run flag overrides every effective LLM-capable module
 binding to use one Scriptorium profile ID: chunk, every selected lane extract,
-merge, and normalize binding.
+merge, and normalize binding. It does not override validator-specific
+`llm_profile` values.
 
 ## Implemented Production Modules
 

docs/internal/pipeline.md

@@ -187,10 +187,10 @@ Runner-side raw validation chains receive the raw module output plus
 stage, lane, module, source, and chunk provenance. Empty raw validation chains
 approve output by default.
 
-Pipeline-configured validator lists are not part of the current runner
-contract. Non-empty configured validator lists are rejected during configuration
-validation or resolved-run validation so they cannot appear in manifests without
-executing.
+Resolved validator chains come from central default mappings unless a
+stage-local config override is set on `chunk`, lane `extract`, lane `merge`, or
+lane `normalize`. Explicit empty overrides are valid and are recorded as empty
+chains in manifests.
 
 Validator rejection is a non-fatal run outcome: the rejected output is recorded
 in `RunOutput.Rejected` and does not pass to the next stage. Validator execution